Transparent display panel having an electrode contact of auxiliary electrode connected to a portion of second electrode and transparent display device including the same

ABSTRACT

A transparent display panel has an auxiliary electrode region including a partition wall whose a width of a top face is larger than that of a bottom face thereof. The auxiliary electrode region is disposed on a line region within a display region. A second electrode of an organic light-emitting element and a VSS voltage connection line is electrically connected to each other via an auxiliary electrode, such that electrical resistance of the second electrode as a transparent electrode is reduced. Further, the auxiliary electrode region is formed on each of a plurality of line regions respectively including VSS voltage connection lines extending across the display region. Thus, a current is fed to each pixel in the display region in a smooth manner, such that luminance distribution across the panel is uniform.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of Korean Patent Application No.10-2019-0146625 filed on Nov. 15, 2019, in the Korean IntellectualProperty Office, the disclosure of which is hereby incorporated byreference in its entirety.

BACKGROUND Technical Field

The present disclosure relates to a transparent display panel to reduceor minimize occurrence of luminance unevenness therein, and atransparent display device including the panel.

Description of the Related Art

A display device that displays various information using an imageincludes a liquid crystal display device (LCD), and an organic lightemitting diode based display device (OLED).

As an image implementation skill is advanced, in recent years, a demandfor a transparent display device in which at least a partial region onwhich information is displayed is transparent to transmits light so thatan object or a background behind the display device is visible to a userin front of the device has increased.

The transparent display device transmits light in front and reardirections. Thus, the device may display information in the front andrear directions of the display device, such that front and rear users infront and rear of the display device may see objects or backgroundsopposite thereto respectively.

For example, the transparent display device implemented as an organiclight-emitting display device may include a transparent region thattransmits incident light as it is and a light-emitting region that emitslight.

BRIEF SUMMARY

In a transparent display device, a transparent electrode having a highsheet resistance is used to improve transparency. Further, when athickness of the transparent electrode is small in order to improvelight transmittance, electrical resistance of the transparent electrodeis further increased.

When the transparent electrode having a high sheet resistance is used,differences between low-level voltage (VSS) rise values at positions ofa display panel become large. Thus, non-uniformity phenomenon ofluminance in the display panel occurs. This may lead to deterioration indisplay quality, especially in a transparent display device having alarge-area display panel.

Accordingly, inventors of the present application have invented atransparent display panel capable of reducing or minimizing occurrenceof non-uniformity of luminance in the display panel via introduction ofan auxiliary electrode region capable of reducing resistance of atransparent electrode, and a transparent display device including thesame.

A purpose of the present disclosure is to provide a transparent displaypanel including an auxiliary electrode region capable of reducingresistance of a transparent electrode, and a transparent display deviceincluding the same.

Further, one or more embodiments of the present disclosure is to providea transparent display panel including a partition wall structure thatmay increase or maximize an electrode contact area to further reducingresistance of a transparent electrode while contributing to improvedtransmittance, and a transparent display device including the same.

Furthermore, one or more embodiments of the present disclosure is toprovide a transparent display panel in which luminance is distributed inan uniform manner via electrical connection between a line region and atransparent electrode arranged in a display region, and a transparentdisplay device including the same.

Furthermore, the present disclosure provides a transparent display panelthat a partition wall acts as a spacer, thereby to remove a process offorming a separate spacer, and a transparent display device includingthe same.

The technical benefits of the present disclosure are not limited to theabove-mentioned benefits. Other benefits and advantages of the presentdisclosure, as not mentioned above, may be understood from the followingdescriptions and more clearly understood from the embodiments of thepresent disclosure. Further, it will be readily appreciated that theadvantages of the present disclosure may be realized by features andcombinations thereof as disclosed in the claims.

A transparent display panel according to an embodiment of the presentdisclosure includes a display region and a non-display region, whereinthe display region includes: a plurality of light-emitting regions; aplurality of transmissive regions; a plurality of line regions spacedfrom each other, each line region extending in one direction; and aplurality of auxiliary electrode regions arranged over a correspondingline region.

In this connection, the light-emitting region includes an organiclight-emitting element including a first electrode, an organiclight-emitting layer, and a second electrode, wherein at least one ofthe line regions includes a VSS voltage connection line, wherein theauxiliary electrode region is disposed on the line region including theVSS voltage connection line.

Specifically, the auxiliary electrode region includes: an auxiliaryelectrode electrically connected to the VSS voltage connection line; apartition wall disposed on the auxiliary electrode, wherein a width of atop face of the partition wall is larger than a width of a bottom facethereof; and an electrode contact composed of a portion of the auxiliaryelectrode and a portion of the second electrode which contact each otherand are electrically connected each other, wherein the electrode contactis positioned inwardly than end of the partition wall

The light-emitting region includes a first color light-emitting region,a second color light-emitting region and a third color light-emittingregion, wherein each of the second color light-emitting region and thethird color light-emitting region is disposed on a corresponding lineregion, wherein the first color light-emitting region is disposedbetween the second color light-emitting region and the third colorlight-emitting region disposed on the different line regions,respectively, wherein the auxiliary electrode region is disposed betweenthe second color light-emitting region and the third colorlight-emitting region disposed on the same line region.

Further, the second electrode may include IZO as a material having highdiffraction properties.

Further, the partition wall may include a first partition wall structureand a second partition wall structure layered on the first partitionwall structure. The first partition wall structure contacts theauxiliary electrode, but the second partition wall structure may bespaced apart from the auxiliary electrode.

According to the present disclosure, introducing the auxiliary electroderegion including the partition wall whose the width of the top face islarger than that of the bottom face thereof on the line region withinthe display region may allow electrically connecting the secondelectrode of the organic light-emitting element and the VSS voltageconnection line to each other via the auxiliary electrode, such thatelectrical resistance of the second electrode as a transparent electrodemay be reduced.

Further, according to the present disclosure, the partition wallstructure including the first partition wall structure as a portion ofthe bank layer and the second partition wall structure stacked on thefirst partition wall structure and spaced apart from the auxiliaryelectrode may allow increasing an area of the electrode contact. Thus,the electrical resistance of the second electrode as a transparentelectrode may be further reduced. The partition wall size may bereduced, thereby improving transmittance.

Further, according to the present disclosure, forming the auxiliaryelectrode region on each of the plurality of line regions respectivelyincluding the VSS voltage connection lines extending across the displayregion may allow supplying a current to each pixel in the display regionin a smooth manner, such that the luminance in the panel may be mademore uniform.

Further, according to the present disclosure, the partition wall of theauxiliary electrode region may be used as a spacer. Thus, a process offorming a separate spacer and a separate region for forming the spacerare not required, thereby to obtain high process efficiency and panelspace utilization.

Further specific effects of the present disclosure as well as theeffects as described above will be described in connection withillustrations of specific details for carrying out the presentdisclosure.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a block diagram schematically illustrating a system of atransparent display device.

FIG. 2 is a plan view for schematically illustrating connection andarrangement relationships of components constituting a transparentdisplay device.

FIG. 3 is a schematic cross-sectional view of light-emitting andtransmissive regions of a pixel in an organic light-emitting displaypanel.

FIG. 4 is a more detailed cross-sectional view of a light-emittingregion of a pixel in an organic light-emitting display panel.

FIG. 5 shows a connection relationship of line connection pads disposedon a first substrate in a transparent display panel according to anembodiment of the present disclosure.

FIG. 6 to FIG. 10 are plan views showing, based on an interlayerstacking structure, a connection relationship between lines of FIG. 5 inthe transparent display panel according to an embodiment of the presentdisclosure.

FIG. 11 is an enlarged plan view of a A-A′ region in FIG. 8 .

FIG. 12 is an enlarged plan view of a B-B′ region of FIG. 11 .

FIG. 13 is an enlarged plan view of a C-C′ region of FIG. 11 .

FIG. 14 is an enlarged plan view of a D-D′ region of FIG. 9 .

FIG. 15 is an enlarged plan view of a E-E′ region of FIG. 10 .

FIG. 16 is an enlarged cross-sectional view of a F-F′ region in FIG. 10.

FIG. 17 is an enlarged plan view of a G-G′ region of FIG. 10 .

FIG. 18 is an enlarged cross-sectional view of a H-H′ region of FIG. 17.

FIG. 19 is an embodiment of a transparent display device used as ahead-up-display.

FIG. 20A shows a long-distance diffraction pattern by a single slit.

FIG. 20B is an illustration of a diffraction effect in a single slit.

FIG. 21A to FIG. 21D show results of a double slit test for a particle,a wave, light and an electron, respectively.

FIG. 22 shows an arrangement of typical quadrangle shaped transmissiveregions in a transparent display device.

FIG. 23 shows diffraction phenomenon of light generated when light isincident onto a central region of a transparent display device havingthe transmissive region shape as shown in FIG. 22 .

FIG. 24 to FIG. 26 show embodiments of the present disclosure in which atransmissive region in a transparent display device has a curved shape.

FIG. 27 shows diffraction phenomenon of light generated when light isincident onto a central region of a transparent display device having acircular transmissive region shape as shown in FIG. 26 .

FIG. 28 and FIG. 29 show embodiments of the present disclosure in whicha transmissive region in a transparent display device has a polygonalshape whose all internal angles are obtuse.

FIG. 30 shows a configuration in which transmissive regions andlight-emitting regions of a transparent display device according to anembodiment of the present disclosure are arranged.

FIG. 31A to FIG. 31C show haze value measurements based on transmissiveregion shape.

FIG. 32 shows haze value measurements based on transmissive regionshapes and based on different ppi.

FIG. 33 shows a configuration in which transmissive regions andlight-emitting regions of a transparent display device according toanother embodiment of the present disclosure are arranged.

FIG. 34 and FIG. 35 show cross-sections of a I-I′ region and a J-J′region in FIG. 30 , respectively.

FIG. 36 and FIG. 37 show a dummy pixel pattern region surrounding theoutermost portion of a display region.

FIG. 38 specifically shows an arrangement relationship between a lineregion and a pixel circuit region in a display region according to anembodiment of the present disclosure.

FIG. 39 shows a circuit of a pixel circuit region connected to a lineregion of a K-K′ region.

FIG. 40 shows a circuit of one pixel circuit region.

FIG. 41 to FIG. 43 show cross-sectional views of L-L′, M-M′, and N-N′regions in FIG. 38 , respectively.

FIG. 44 shows a specific arrangement relationship between a line regionand an auxiliary electrode region in a display region according to anembodiment of the present disclosure.

FIG. 45 is a cross-sectional view of Q-Q′ and R-R′ regions in FIG. 44 .

FIG. 46A and FIG. 46B are enlarged cross-sectional views of a S-S′region in FIG. 45 in a first embodiment and a second embodiment,respectively.

FIG. 47A shows a region of an electrode contact that may be formed whena partition wall of a single layer having an inverse tapered shape isformed.

FIG. 47B shows a region of an electrode contact that may be formed whena partition wall including a stack of a first partition wall structureand a second partition wall structure of an inverse tapered shape.

FIG. 48A and FIG. 48B show ΔVSS values in a case where a partition wallis present and a case in where the partition wall is absent,respectively.

FIG. 49A shows variations of an area and an electrical resistance of anelectrode contact based on a width of the partition wall.

FIG. 49B shows variations of an area and an electrical resistance of anelectrode contact based on a size of an open region of a bank layer.

DETAILED DESCRIPTIONS

For simplicity and clarity of illustration, elements in the figures arenot necessarily drawn to scale. The same reference numbers in differentfigures represent the same or similar elements, and as such performsimilar functionality. Further, descriptions and details of well-knownsteps and elements are omitted for simplicity of the description.Furthermore, in the following detailed description of the presentdisclosure, numerous specific details are set forth in order to providea thorough understanding of the present disclosure. However, it will beunderstood that the present disclosure may be practiced without thesespecific details. In other instances, well-known methods, procedures,components, and circuits have not been described in detail so as not tounnecessarily obscure aspects of the present disclosure.

Examples of various embodiments are illustrated and described furtherbelow. It will be understood that the description herein is not intendedto limit the claims to the specific embodiments described. On thecontrary, it is intended to cover alternatives, modifications, andequivalents as may be included within the spirit and scope of thepresent disclosure.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to limit the present disclosure. Asused herein, the singular forms “a” and “an” are intended to include theplural forms as well, unless the context clearly indicates otherwise. Itwill be further understood that the terms “comprises”, “comprising”,“includes”, and “including” when used in this specification, specify thepresence of the stated features, integers, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, operations, elements, components, and/orportions thereof. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. Expressionsuch as “at least one of” when preceding a list of elements may modifythe entire list of elements and may not modify the individual elementsof the list.

It will be understood that, although the terms “first”, “second”,“third”, and so on may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. Thus, a first element, component, region, layer or sectiondescribed below could be termed a second element, component, region,layer or section, without departing from the spirit and scope of thepresent disclosure.

In addition, it will also be understood that when a first element orlayer is referred to as being present “on” or “beneath” a second elementor layer, the first element may be disposed directly on or beneath thesecond element or may be disposed indirectly on or beneath the secondelement with a third element or layer being disposed between the firstand second elements or layers.

It will be understood that when an element or layer is referred to asbeing “connected to”, or “coupled to” another element or layer, it maybe directly on, connected to, or coupled to the other element or layer,or one or more intervening elements or layers may be present. Inaddition, it will also be understood that when an element or layer isreferred to as being “between” two elements or layers, it may be theonly element or layer between the two elements or layers, or one or moreintervening elements or layers may also be present.

Further, as used herein, when a layer, film, region, plate, or the likeis disposed “on” or “on a top” of another layer, film, region, plate, orthe like, the former may directly contact the latter or still anotherlayer, film, region, plate, or the like may be disposed between theformer and the latter. As used herein, when a layer, film, region,plate, or the like is directly disposed “on” or “on a top” of anotherlayer, film, region, plate, or the like, the former directly contactsthe latter and still another layer, film, region, plate, or the like isnot disposed between the former and the latter. Further, as used herein,when a layer, film, region, plate, or the like is disposed “below” or“under” another layer, film, region, plate, or the like, the former maydirectly contact the latter or still another layer, film, region, plate,or the like may be disposed between the former and the latter. As usedherein, when a layer, film, region, plate, or the like is directlydisposed “below” or “under” another layer, film, region, plate, or thelike, the former directly contacts the latter and still another layer,film, region, plate, or the like is not disposed between the former andthe latter.

Unless otherwise defined, all terms including technical and scientificterms used herein have the same meaning as commonly understood by one ofordinary skill in the art to which this inventive concept belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, a transparent display panel according to some embodimentsof the present disclosure and a transparent display device including thesame will be exemplified.

FIG. 1 is a block diagram for schematically illustrating a transparentdisplay device according to an embodiment of the present disclosure.FIG. 2 is a plan view for schematically illustrating connection andarrangement relationships of components constituting a transparentdisplay device.

However, each of FIG. 1 and FIG. 2 is one embodiment according to thepresent disclosure. Thus, the connection and arrangement relationshipsof the components of the transparent display device 100 according to thepresent disclosure are not limited thereto.

The transparent display device 100 may include a transparent displaypanel 110, a timing controller 140, a data driver 120, and a gate driver130.

The transparent display panel 300 may include a display region DAcontaining at least one pixel P to display an image, and a non-displayregion NDA in which an image is not displayed.

The non-display region NDA may be disposed to surround the displayregion DA.

In the non-display region NDA, the gate driver 130, a data drive IC pad310, and various lines may be disposed. The non-display region NDA maycorrespond to a bezel.

The transparent region of the transparent display panel 300 may becontained in both the display region DA and the non-display region NDA.

The transparent display panel 300 may include a plurality of pixelregions defined by a plurality of gate lines GL extending in a firstdirection, and a plurality of data lines DL extending in a seconddirection orthogonal to the gate lines GL.

The pixel regions may be arranged in a matrix form. Each pixel regionmay include a pixel P composed of at least one sub-pixel SP.

The gate driver 130 is directly stacked on the transparent display panel110 in a form of GIP (Gate In Panel).

A plurality of GIP circuit regions may be arranged in the GIP form andmay be disposed in left and right portions of the non-display region NDArespectively adjacent to left and right outer peripheral portions of thedisplay region DA while the display region DA is interposed between theleft and right portions of the non-display region NDA.

The data driver 120 may include at least one source driver integratedcircuit 121 (source driver IC) to drive a plurality of data lines DL.

For example, a source driving chip corresponding to each source driverintegrated circuit 121 may be mounted on a flexible film 123. One end ofthe flexible film 123 may be bonded to at least one control printedcircuit board 150, while the other end thereof may be bonded to a datadrive IC pad (DDPA) of the transparent display panel 110.

The timing controller 140 may be disposed on the control printed circuitboard 150. Further, a power controller may be further disposed on thecontrol printed circuit board 150.

In addition, a source printed circuit board may be disposed between theflexible film 123 and the control printed circuit board 150 while thesource printed circuit board is connected thereto via a connectionmedium such as a flexible flat cable (FFC) or a flexible printed circuit(FPC).

In one example, the transparent display device 100 may be embodied as aliquid crystal display device, an organic light-emitting display device,etc. However, the present disclosure is not limited thereto.Hereinafter, in accordance with an embodiment of the present disclosure,an example in which the transparent display device 100 may be embodiedas an organic light-emitting display device will be described withreference to FIG. 3 and FIG. 4 .

The transparent display panel may include a first substrate 200 and asecond substrate 270.

The first substrate 200 may act as a base substrate including a displayregion DA in which pixels are disposed, and a non-display region NDA.

The second substrate 270 may be opposite to the first substrate 200 andmay act as an encapsulating substrate.

Each of the first substrate 200 and the second substrate 270 may beembodied as a plastic substrate or a glass substrate.

The display region DA of the first substrate 200 includes alight-emitting region EA and a transmissive region TA.

A plurality of sub-pixels may be arranged in the light-emitting regionEA.

Each sub-pixel may be a red sub-pixel emitting red light, or may be agreen sub-pixel emitting green light, or may be a blue sub-pixelemitting blue light, or may be a sub-pixel emitting light, for example,white light other than the red, green or blue light.

Each sub-pixel may include a light-emitting region EA for emitting lightof a corresponding color, and a circuit region electrically connected tothe light-emitting region EA to control light-emission from thelight-emitting region EA.

The light-emitting region of the sub-pixel EA may refer to a region inwhich light of a corresponding color to each sub-pixel is emitted or mayrefer to a pixel electrode such as an anode electrode that exists ineach sub-pixel, or may mean a region where the pixel electrode isdisposed.

The light-emitting region EA includes an organic light-emitting element220 including an anode electrode as a first electrode 221, an organiclight-emitting layer 223, and a cathode electrode as a second electrode225. The organic light-emitting element 220 emits light at a predefinedbrightness using a voltage supplied to the first electrode 221 and avoltage supplied to the second electrode 225.

In this case, the second electrode 225 as a transparent electrode mayextend across both the light-emitting region EA and the transmissiveregion TA.

The circuit region of the sub-pixel means a circuit region including thedriving thin-film transistor 210 that supplies a voltage or a current tothe pixel electrode of each sub-pixel to control light emission from thelight-emitting region EA or may mean a region in which the circuitregion is disposed.

The driving thin-film transistor 210 includes a gate electrode 214, asource electrode 217 a, a drain electrode 217 b and an active layer 212.

When the circuit region receives a gate signal from the gate line GLusing the thin-film transistors, the circuit region may supply apredefined voltage to the first electrode 221 of the organiclight-emitting element 220 of the light-emitting region EA based on adata voltage of the data line DL.

The circuit region may vertically at least partially overlap thelight-emitting region EA, but may be disposed at an opposite side to aside from which light is emitted so as not to interfere with the lightemission.

An encapsulating layer 250 is formed on the organic light-emittingelement 220, specifically, the second electrode 225 thereof. A colorfilter 260 corresponding to the organic light-emitting element 220 maybe formed on the encapsulating layer 250.

The color filter 260 may have the same color as or a different colorfrom that of a corresponding sub-pixel.

The transmissive region TA refers to a region that transmits incidentlight, and may be a region excluding the circuit region. A transmittanceof the transparent display device depends on an area of the transmissiveregion TA.

FIG. 3 shows one embodiment of the present disclosure in which thelight-emitting region EA and the transmissive region TA corresponds toone sub-pixel. However, the present disclosure is not limited thereto.The arrangement form of the light-emitting region EA and thetransmissive region TA of the transparent display device according tothe present disclosure is not limited thereto. FIG. 4 is a more detailedcross-sectional view of a light-emitting region EA corresponding to onesub-pixel in an organic light-emitting display device according to anembodiment of the present disclosure.

Over the first substrate 200, a driving thin-film transistor 210, and anorganic light-emitting element 220 are disposed. A buffer layer 201 maybe formed on the first substrate 200, and a gate insulation layer 213may be formed on the active layer 213, and an interlayer insulationlayer 216 may be formed on the gate electrode 214.

More specifically, as shown in FIG. 4 , a buffer layer 201 is formed onthe first substrate 200, a gate insulating layer 213 is formed on thebuffer layer 201 to cover an active layer 212 of the driving thin-filmtransistor 210, and an interlayer insulating layer 216 is formed on thegate insulating layer 213 to cover a gate electrode 214 of the drivingthin-film transistor 210.

A passivation layer 218 may be formed on the driving thin-filmtransistor 210 to cover the driving thin-film transistor 210. Acontact-hole exposing a drain electrode 217 b may be formed in thepassivation layer 218.

The passivation layer 218 may act as a planarization layer made of anorganic insulating material.

The first electrode 221 constituting the organic light-emitting element220 is formed on the passivation layer 218. The first electrode 221 iselectrically connected to the drain electrode 217 b via the contact-holedefined in the passivation layer 218. Thus, the driving thin-filmtransistor 210 and the first electrode 221 may be electrically connectedto each other.

The first electrode 221 may act as an anode electrode that serves toinject holes. In this case, the first electrode may be embodied as atransparent electrode made of at least one transparent conductivematerial such as indium tin oxide (ITO), antimony tin oxide (ATO), andindium zinc oxide (IZO).

A bank layer 231 is formed on and over the passivation layer 218.Sub-pixels may be separated from each other via the bank layer 231 toform a border between adjacent light-emitting region EAs to rendercorresponding colors, respectively. The bank layer 231 may have abank-hole defined therein corresponding to a sub-pixel region topartially expose the first electrode 221.

The organic light-emitting layer 223 may be formed on a top face of thebank layer 231 and on a top face of a portion of the first electrode 221exposed through the bank-hole. A region where the organic light-emittinglayer 223 contacts the first electrode 221 may correspond to a sub-pixelregion, more specifically, the light-emitting region EA.

The organic light-emitting layer 223 may include a hole injection layer(HIL), a hole transport layer (HTL), a light-emitting layer (EML), anelectron transport layer (ETL), an electron injection layer (EIL).

The light-emitting layer (EML) may emit red R, green G or blue B lightand may be made of a phosphorescent material or a fluorescent materialthat emits a corresponding color.

In this case, each of the hole injection layer (HIL), the hole transportlayer (HTL), the electron transport layer (ETL), and the electroninjection layer (EIL) may occupy an entire display region. Thelight-emitting layer EML may be patterned to correspond to each colorregion, specifically, the first electrode 221. Further, each of the holeinjection layer (HIL), the hole transport layer (HTL), the electrontransport layer (ETL), and the electron injection layer (EIL) may bepatterned to correspond to each color region, specifically, the firstelectrode 221.

In some embodiments, the second electrode 225 is formed on the organiclight-emitting layer 223 and over an entirety of the first substrate200. The second electrode 225 is disposed on an entirety of the displayregion DA of the first substrate 200. In this case, the second electrode225 may be disposed on an entirety of the display region DA except forthe transmissive region TA.

The second electrode 225 may act as a cathode electrode that serves toinject electrons.

In this case, the second electrode 225 may include at least one ofmaterials such as Ca, Al:Li, Mg:Ag, and Ag. Further, the secondelectrode 225 may be embodied as a transparent electrode made of atleast one of transparent conductive materials such as indium tin oxide(ITO), antimony tin oxide (ATO), and indium zinc oxide (IZO).

On the organic light-emitting element 220, an encapsulating layer 250 isformed that prevents external moisture from penetrating the organiclight-emitting element 220.

On the encapsulating layer 250, the second substrate 270 as theencapsulating substrate opposite to the first substrate 200 may beformed.

In this case, a barrier layer may be formed between the encapsulatinglayer 250 and the second substrate 270 to more effectively preventexternal moisture or oxygen from penetrating the organic light-emittingelement 220.

FIG. 5 shows a connection relationship of line connection pads disposedon the first substrate 301 in the transparent display panel 300according to an embodiment of the present disclosure.

The first substrate 301 includes a display region DA and a non-displayregion NDA disposed to surround the display region DA. The non-displayregion NDA may surround top, bottom, left, and right sides of thedisplay region DA. A vertical or up-down direction of the display regionDA refers to a Y-axis direction, while a horizontal or left-rightdirection of the display region DA refers to a X-axis direction.

The display region DA may have a rectangular shape including long sidesand short sides.

In this case, the long side is relatively longer than the short side.

Further, the long side means a side parallel to the X-axis direction asthe left and right direction of the display region DA.

The short side means a side parallel to the Y-axis direction as thevertical or up-down direction of the display region DA.

The gate driver 130 may be disposed in a form of GIP (gate in panel) andon at least one side to the display region DA.

In other words, a pair of GIP circuit regions 360 are disposed inportions of the non-display region NDA located on the left and rightsides to the display region DA respectively.

For example, the GIP circuit region 360 is disposed along the short sideof the display region DA. A first VSS voltage line 321 and a second VSSvoltage line 322 may be disposed along the long side of the displayregion DA.

On one portion of the non-display region NDA where the GIP circuitregion 360 is disposed, a GIP ESD (electro-static discharge) protectioncircuit region 365 that operates when static electricity is introducedinto the GIP circuit region 360 to reduce or minimize static electricityinflow may be disposed.

At least one data drive IC pad 310 may be disposed on one side to thedisplay region DA where the GIP circuit region 360 is not disposed, forexample, at a portion of the non-display region NDA above a top longside of the display region DA.

The data drive IC pad 310 is connected to various lines necessary fordriving the transparent display panel 300 such as the power line and thedata line.

Between the data drive IC pad 310 and the display region DA, a data lineconnection pad 311, a reference voltage line connection pad 340, a VSSvoltage line connection pad 320, and a VDD voltage line connection pad330 are disposed to be connected to each other via the data drive IC pad310 and various lines.

Specifically, each of right and left reference voltage line connectionpads 340, each of right and left VDD voltage line connection pads 330,and each of right and left VSS voltage line connection pads 320 may bedisposed adjacent to each of right and left portions of the data driveIC pad 310. A spacing between each of right and left reference voltageline connection pads 340 and a length direction center of the data driveIC pad 310 is smaller than a spacing between each of right and left VDDvoltage line connection pads 330 and the length direction center of thedata drive IC pad 310 which is smaller than a spacing between each ofright and left VSS voltage line connection pads 320 and the lengthdirection center of the data drive IC pad 310.

That is, the both reference voltage line connection pads 340, the bothVDD voltage line connection pads 330, and the both VSS voltage lineconnection pads 320 may be arranged symmetrically to each other around acenter of the data line connection pad 311. In one or more embodiments,the term “symmetrically” used throughout in the specification is used toinclude the meaning of both symmetrically and substantiallysymmetrically.

The reference voltage line connection pad 340, the VDD voltage lineconnection pad 330, and the VSS voltage line connection pad 320 arearranged to be spaced apart from each other.

The VDD voltage line connection pad 330 may act as a high-level voltagepower line connection pad that supplies high-level voltage power to apixel for driving the pixel, while the VSS voltage line connection pad320 may act as a low-level voltage power line connection pad thatapplies low-level voltage power to the pixel for driving the pixel.

The reference voltage line connection pad 340 may supply a referencevoltage Vref to a pixel.

A reference voltage line 341 electrically connected to the referencevoltage line connection pad 340, a first VDD voltage line 331electrically connected to the VDD voltage line connection pad 330, and afirst VSS voltage line 321 electrically connected to the VSS voltageline connection pad 320 may be disposed between the reference voltageline connection pad 340 and the display region DA, between the VDDvoltage line connection pad 330 and the display region DA, and betweenthe VSS voltage line connection pad 320 and the display region DA,respectively.

In one embodiment of the present disclosure, the VDD voltage lineconnection pad 330 and the first VDD voltage line 331 are integrallyformed with each other, the reference voltage line connection pad 340and the reference voltage line 341 are formed to be spaced apart fromeach other and electrically connected to each other via a separateconnection electrode, and the VSS voltage line connection pad 320 andthe first VSS voltage line 321 are formed to be spaced apart from eachother and electrically connected to each other via a separate connectionelectrode. However, the present disclosure is not limited thereto.

The first VDD voltage line 331 may be formed to have a bar shape, andmay extend parallel to one side face of the display region DA,specifically, along the long side of the display region DA and may beintegrally formed with the VDD voltage line connection pad 330. In oneor more embodiments, a bar shape may include a rectangular bar shape, anelongated bar shape or even a bar shape closer to a square bar shape, orany other suitable shape for being implemented in a display device.

Further, the first VDD voltage line 331 may be formed integrally with aplurality of VDD voltage line connection pads 330 corresponding to eachdata drive IC pad 310 to electrically connect the plurality of VDDvoltage line connection pads 330 to each other.

The reference voltage line 341 may be disposed between the first VDDvoltage line 331 and the display region DA. In one embodiment of thepresent disclosure, an example in which the reference voltage line mayact as the initial voltage line will be described. However, the presentdisclosure is not limited thereto. Depending on a compensation circuitregion, the reference voltage line 341 may act as a separate line fromthe initial voltage line.

Thus, the reference voltage line connection pad 340 may be disposed tobe spaced apart from the reference voltage line 341 in the Y directionwhile a spacing between the former and the display region DA is largerthan a spacing between the latter and the display region DA.

The reference voltage line 341 may be formed to have a bar shape, andmay extend parallel to the first VDD voltage line 331.

In order to apply the reference voltage to the reference voltage line341, the reference voltage line connection pad 340 and the referencevoltage line 341 may be electrically connected to each other via asecond connection electrode 352 as a separate connection electrode.

The first VSS voltage line 321 may be disposed between the referencevoltage line 341 and the display region DA.

Thus, the VSS voltage line connection pad 320 may be disposed to bespaced apart from the first VSS voltage line 321 in the Y directionwhile a spacing between the former and the display region DA is largerthan a spacing between the latter and the display region DA.

The first VSS voltage line 321 may be formed to have a bar shape and mayextend in parallel with the first VDD voltage line 331 and the referencevoltage line 341.

In order to apply the VSS voltage to the first VSS voltage line 321, theVSS voltage line connection pad 320 and the first VSS voltage line 321may be electrically connected to each other via a first connectionelectrode 351 as a separate connection electrode.

Further, a VSS voltage auxiliary line connection pad 326 as a separateportion from the VSS voltage line connection pad 320 may be disposedbetween the left and right reference voltage line connection pads 340.

Specifically, the VSS voltage auxiliary line connection pad 326 may havea form of an island spaced from and disposed between the left and rightreference voltage line connection pads 340 and spaced from and disposedbetween the data line connection pad 311 and the VDD voltage line.

The VSS voltage auxiliary line connection pad 326 may be electricallyconnected to the first VSS voltage line 321 via the first connectionelectrode 351.

In this way, when the VSS voltage auxiliary line connection pad 326 iselectrically connected to the first VSS voltage line 321 via the firstconnection electrode 351, an entire contact area of the first VSSvoltage line 321 is enlarged, thereby to keep a resistance distributionof the first VSS voltage line 321 uniform while lowering an overallresistance thereof.

An ESD protection circuit region 371 may be disposed between thereference voltage line 341 and the display region DA. A multiplexer(MUX) circuit region 373 may be disposed between the first VSS voltageline 321 and the display region DA. However, the present disclosure isnot limited thereto. The positions of ESD protection circuit region 371and MUX circuit region 373 may vary based on a design scheme of thetransparent display panel 300. Further, in some embodiments, the MUXcircuit region 373 may be disposed between the first VSS voltage line321 and a dummy pixel pattern region DPA that is adjacent to the displayregion DA (see FIG. 36 ).

The ESD protection circuit region 371 may include a plurality ofthin-film transistors constituting an ESD protection circuit. Whenstatic electricity is generated from the transparent display panel 300,the ESD protection circuit region operates to take out staticelectricity to an outside.

The MUX circuit region 373 may be configured to include a plurality ofthin-film transistors constituting a MUX circuit.

When using the MUX circuit region 373, one channel of a driver IC outputmay supply a signal to two or more data lines 313. This has an advantageof reducing the number of driver ICs as used.

Each of the ESD protection circuit region 371 and the MUX circuit region373 may be formed in a bar shape extending parallel to the referencevoltage line 341 and the like. However, the present disclosure is notlimited thereto.

The first VDD voltage line 331 and the first VSS voltage line 321 may bedisposed in an upper portion of the non-display region NDA adjacent toan upper side of the display region DA, while a second VDD voltage line332 and a second VSS voltage line 322 may be disposed in a lower portionof the non-display region NDA adjacent to a lower side of the displayregion DA.

The second VDD voltage line 332 and the second VSS voltage line 322 maybe spaced from each other while a spacing between the former and thedisplay region DA is smaller than a spacing between the latter and thedisplay region DA.

The second VDD voltage line 332 may be formed to have a bar shape, andmay extend in parallel along one side face of the display region DA,specifically, along the long side of the display region DA.

In order to apply the VDD voltage to the second VDD voltage line 332,the first VDD voltage line 331 and the second VDD voltage line 332 maybe electrically connected to each other via a separate connectionelectrode as a VDD voltage connection line 333.

Therefore, using the connection structure as described above, the VDDvoltage supplied via the VDD voltage line connection pad 330 may beapplied to the second VDD voltage line 332 via the first VDD voltageline 331 and the VDD voltage connection line 333.

In this case, at least one VDD voltage connection line 333 is disposedin the display region DA to extend across the display region DA and thuselectrically connects the first VDD voltage line 331 and the second VDDvoltage line 332 to each other.

In one example, the second VSS voltage line 322 may be formed to have abar shape, and may extend in parallel along one side face of the displayregion DA, specifically, along the long side of the display region DA.

A width W₂ of the second VSS voltage line 322 may be smaller than awidth W₁ of the first VSS voltage line 321, such that the second VSSvoltage line 322 is thinner than the first VSS voltage line 321.

In order to apply the VSS voltage to the second VSS voltage line 322,the first VSS voltage line 321 and the second VSS voltage line 322 maybe electrically connected to each other via a separate connectionelectrode as a VSS voltage connection line 323.

Therefore, using the connection structure as described above, the VSSvoltage supplied via the VSS voltage line connection pad 320 may beapplied to the second VSS voltage line 322 via the first VSS voltageline 321 and the VSS voltage connection line 323.

In this case, at least one VSS voltage connection line 323 may bedisposed in the display region DA to extend across the display region DAand thus electrically connects the first VSS voltage line 321 and thesecond VSS voltage line 322 to each other.

As in one embodiment of the present disclosure, the first VSS voltageline 321 and the second VSS voltage line 322 disposed above and belowthe display region DA may be electrically connected to each other via atleast one VSS voltage connection line 323 extending across the displayregion DA. Thus, following effects may be realized.

First, non-transparent VSS voltage lines located at left and rightportions of the non-display region on the left and right sides to thedisplay region DA may be omitted. Thus, the transparent region of thebezel may be enlarged, so that the transparent region in the bezel maybe increased or maximized.

Further, non-transparent VSS voltage lines located at left and rightportions of the non-display region on the left and right sides to thedisplay region DA may be omitted. Thus, the VSS voltage line-connectionregions required to allow the VSS voltage lines to be placed on bezelportions left and right to the display region DA are not needed. Thus,the bezel may be slim.

For example, when the VSS voltage connection line 323 is disposed ineach of left and right portions of the non-display region NDA left andright to the display region DA, the VSS voltage line is disposed tosurround the display region DA and extends along an outer periphery ofthe display region DA. In this case, a size of the transparent region ofthe bezel is reduced because the non-transparent VSS voltage line isformed in the non-display region NDA out of the outer periphery of thedisplay region DA, thereby to disallow reduction of the bezel area.

However, in the VSS voltage line arrangement structure according to anembodiment of the present disclosure, the VSS voltage lines are notdisposed on the top, bottom, left, and right sides to the display regionDA, that is, on four side portions of the bezel. Rather, it may sufficethat the VSS voltage lines are disposed only on top and bottom sideportions of the bezel up and down to the display region DA.

Therefore, according to an embodiment of the present disclosure, amaximum of a transparent region of a bezel where the non-transparent VSSvoltage line is not disposed may be secured. When necessary, a size ofthe bezel may be reduced, so that the bezel may be slimmer.

Further, when the VSS voltage line surrounds the outer periphery of thedisplay region DA, the VSS voltage flows around the outer periphery ofthe display region DA and flows into the display region DA and then issupplied to the pixels in the display region DA. Thus, the VSS voltageline which serves as a current path must be thick in order to functionas the current path in a reliable manner in terms of the electricalresistance.

However, in one embodiment of the present disclosure, while the VSSvoltage connection line 323 passes across the display region DA, the VSSvoltage connection line may directly supply the VSS voltage to thepixel. Thus, the second VSS voltage line 322 may not serve as a currentpath.

In this way, when the second VSS voltage line 322 does not serve as thecurrent path, the second VSS voltage line 322 does not need to be formedto be thick in consideration of the electrical resistance and thus be asthin as possible.

Therefore, according to an embodiment of the present disclosure, thesecond VSS voltage line 322 may have a width smaller than that of thefirst VSS voltage line 321. Thus, as the width of the second VSS voltageline 322 decreases, a size of a transparent region in a lower bezelportion below the display region DA may be increased. When necessary,the bezel may be made slimmer.

A lighting tester 375 may be disposed in the non-display region NDA andbe spaced apart from the second VSS voltage line 322 while a spacingbetween the former and the display region DA is larger than a spacingbetween the latter and the display region DA.

The lighting tester 375 may be formed in a bar shape extending parallelto the second VSS voltage line 322, and may further extend along bothleft and right sides of the display region DA, thereby to surround threesides of the display region DA.

The lighting tester 375 may supply a lighting test signal to a pluralityof data lines 313 before a module process after the transparent displaypanel 300 is manufactured and may inspect a defect of the transparentdisplay panel 300.

The lighting tester 375 includes a plurality of inspection switchingelements connected to the plurality of data lines 313 respectively.

Therefore, the plurality of data lines 313 branched from the data lineconnection pad 311 extend across the display region DA and then areelectrically connected to the lighting tester 375.

A lighting test signal applicator 376 may be formed on a partial regionof each of the reference voltage line connection pad 340, the VDDvoltage line connection pad 330, and the VSS voltage line connection pad320 to supply the lighting test signal to the lighting tester 375.

FIG. 6 to FIG. 10 are plan views showing, based on an interlayerstacking structure, a connection relationship between the lines of FIG.5 in the transparent display panel 300 according to an embodiment of thepresent disclosure.

As shown in FIG. 6 , the reference voltage line connection pad 340, theVDD voltage line connection pad 330, the VSS voltage line connection pad320, the VSS voltage auxiliary line connection pad 326, the referencevoltage line 341, the first VDD voltage line 331, the second VDD voltageline 332, the first VSS voltage line 321 and the second VSS voltage line322 of the transparent display panel 300 according to an embodiment ofthe present disclosure may constitute the same layer and may be spacedapart from each other. In some embodiments where appropriate, constitutethe same layer means that the elements (or components) are formed of thesame layer (or in some cases are formed on the same layer).

The reference voltage line connection pad 340, the VDD voltage lineconnection pad 330, the VSS voltage line connection pad 320, the VSSvoltage auxiliary line connection pad 326, the reference voltage line341, the first VDD voltage line 331, the second VDD voltage line 332,the first VSS voltage line 321, the second VSS voltage line 322, thesource electrode 217 a, and the drain electrode 217 b of the drivingthin-film transistor 210 of a pixel may be made of the same material andmay constitute the same layer.

However, as illustrated above, the VDD voltage line connection pad 330and the first VDD voltage line 331 may be integrally formed with eachother without being separated from each other.

Thus, the line connection pads and the lines constitute the same layer.Thus, the connection electrodes that electrically connect the lineconnection pads and the lines to each other should not form ashort-circuit with other lines between the line connection pad and theline to be connected to each other, or between the lines.

For example, in order to connect the data lines 313 branched from thedata line connection pad 311 to the lighting tester 375, the data line313 may be composed of a first data line 314 and a second data line 315which constitute different layers and are electrically connected to eachother.

In this case, the first data line 314, the source electrode 217 a, anddrain electrode 217 b of the driving thin-film transistor 210 of thepixel may constitute the same layer and may be made of the samematerial. The second data line 315, and the gate electrode 214 of thedriving thin-film transistor 210 of the pixel may constitute the samelayer and may be made of the same material.

The data line 313 applies a data signal to pixels in the display regionDA. Thus, the first and second data lines 314 and 315 of the data line313 branched from the data line connection pad 311 may constitutedifferent layers so as not to form a short-circuit with various lineconnection pads and lines disposed in a region between the displayregion DA and the data line connection pad 311.

Thus, the second data line 315 may act as the data line 313 in a regionbetween the display region DA and the data line connection pad 311. Thefirst data line 314 constituting a different layer from a layer of thesecond data line 315 may act as the data line 313 in the display region.

Then, the second data line 315 may act as the data line 313 in a regionbetween the display region DA and the lighting tester 375. Then, thefirst data line 314 as the data line 313 may be connected to thelighting tester 375.

However, the first data line 314 and the second data line 315 may act asthe data line 313 in a repeatedly alternate manner such that the dataline 313 does not form a short-circuit with the second VDD voltage line332 and the second VSS voltage line 322 in regions in which the dataline 313 overlaps the second VDD voltage line 332 and the second VSSvoltage line 322 in a region between the display region DA and thelighting tester 375.

The data line 313 may change from the first data line 314 to the seconddata line 315 in a region where the data line 313 does not overlap thesecond VDD voltage line 332, such that the data line 313 does not form ashort-circuit with the second VDD voltage line 332 while extendingacross the second VDD voltage line 332. In this way, the second dataline 315 and the second VDD voltage line 332 do not constitute the samelayer, thereby preventing the short circuit therebetween.

In the connection, the data line 313 changing from the first data line314 to the second data line 315 may mean that, as shown in FIG. 12 , thefirst data line 314 is connected to the second data line 315 via atleast one contact-hole such that electrical connection therebetween ismaintained, but the first data line 314 and the second data line 315constitute different layers and are made of the different materials.This principle may be equally applied to other lines as exemplifiedbelow.

After the second data line 315 extends across the second VDD voltageline 332, the second data line may be changed back to the first dataline 314 in a region where the data line 313 does not overlap the secondVDD voltage line 332.

That is, the first data line 314 and the second data line 315 mayconstitute different layers and are electrically connected to each othervia at least one second data line contact-hole 315 h.

In the same manner, the reference voltage connection line 343 may becomposed of a first reference voltage connection line 344 and a secondreference voltage connection line 345 which constitute different layersand are electrically connected to each other.

In this case, the first reference voltage connection line 344, thesource electrode 217 a and the drain electrode 217 b may constitute thesame layer and may be made of the same material. The second referencevoltage connection line 345 and the gate electrode 214 may constitutethe same layer and may be made of the same material.

For example, the reference voltage connection line 343 extends to alower end of the display region DA. The reference voltage connectionline 343 may be composed of the first reference voltage connection line344 and the second reference voltage connection line 345 whichconstitute different layers and are electrically connected to eachother. The reference voltage connection line 343 extends across thedisplay region DA. A distal end of the reference voltage connection line343 need not contact a separate line.

Because the reference voltage connection line 343 applies a referencevoltage to pixels in the display region DA, the reference voltageconnection line 343 is composed of different reference voltageconnection lines constituting different layers such that the referencevoltage connection line 343 does not form a short-circuit with variousline connection pads and lines in a region between the display region DAand the reference voltage line 341.

Thus, the reference voltage connection line 343 is embodied as thesecond reference voltage connection line 345 in a region between thedisplay region DA and the reference voltage line 341. In the displayregion DA, the reference voltage connection line 343 is embodied as thefirst reference voltage connection line 344 which constitutes adifferent layer from that of the second reference voltage connectionline 345.

The first reference voltage connection line 344 and the second referencevoltage connection line 345 may constitute different layers and may beelectrically connected to each other via at least one contact-hole.Further, the VSS voltage connection line 323 may be composed of a firstVSS voltage connection line 324 and a second VSS voltage connection line325 constituting different layers and being electrically connected toeach other.

In this case, the first VSS voltage connection line 324, the sourceelectrode 217 a and drain electrode 217 b may constitute the same layerand may be made of the same material. The second VSS voltage connectionline 325 and the gate electrode 214 may constitute the same layer andmay be made of the same material.

For example, in order to connect the VSS voltage connection line 323 tothe second VSS voltage line 322, the first VSS voltage connection line324 and the second VSS voltage connection line 325 constitutingdifferent layers are electrically connected to each other.

Since the VSS voltage connection line 323 electrically connects thefirst VSS voltage line 321 and the second VSS voltage line 322sandwiching the display regions DA therebetween to each other, the firstVSS voltage connection line 324 and the second VSS voltage connectionline 325 of the VSS voltage connection line may constitute differentlayers such that the VSS voltage connection line does not form ashort-circuit with various line connection pads and lines in a regionbetween the first VSS voltage line 321 and the second VSS voltage line322.

In one embodiment of the present disclosure, no other line is disposedbetween the display region DA and the first VSS voltage line 321. Thus,the VSS voltage connection line 323 extending from the first VSS voltageline 321 may be embodied as the first VSS voltage connection line 324integrally formed with the first VSS voltage line 321 and made of thesame material as that of the first VSS voltage line 321 and constitutingthe same layer with the first VSS voltage line 321.

The first VSS voltage connection line 324 branched from the first VSSvoltage line 321 may extend across the display region DA. Then, when theVSS voltage connection line 323 extends across the second VDD voltageline 332, the first VSS voltage connection line 324 and the second VSSvoltage connection line 325 may act as the VSS voltage connection line323 in a repeatedly alternate manner such that the VSS voltageconnection line 323 does not form a short-circuit with the second VDDvoltage line 332 in a region where the VSS voltage connection line 323overlaps the second VDD voltage line 332.

When the VSS voltage connection line 323 extends across the second VDDvoltage line 332, the VSS voltage connection line 323 may change fromthe first VSS voltage connection line 324 to the second VSS voltageconnection line 325 in a region where the VSS voltage connection line323 does not overlap the second VDD voltage line 332. Thus, when the VSSvoltage connection line 323 extends across the second VDD voltage line332, the VSS voltage connection line 323 does not form a short-circuitwith the second VDD voltage line 332.

That is, the first VSS voltage connection line 324 and the second VSSvoltage connection line 325 constitute different layers and areelectrically connected to each other via at least one second VSS voltageconnection line contact-hole 325 h.

After the VSS voltage connection line 323 has extended across the secondVDD voltage line 332, the first VSS voltage connection line 324 may beconnected to the second VSS voltage line 322, as shown in FIG. 13 .

In this case, the first VSS voltage connection line 324 and the secondVSS voltage line 322 may be electrically connected to each other via asecond VSS voltage connection line 325 connected to the first VSSvoltage connection line 324 via at least one second VSS voltageconnection line contact-hole 325 h.

In addition, in a region where the second VSS voltage line 322 does notoverlap the data line 313, auxiliary lines 327 connected to the secondVSS voltage line 322 via at least one auxiliary line contact-hole 327 hare disposed below the second VSS voltage line 322.

The auxiliary line 327 and the gate electrode 214 may be made of thesame material and may constitute the same layer.

The auxiliary line 327 may be connected to a rear face of the second VSSvoltage line 322, thereby reducing an overall resistance of the secondVSS voltage line 322.

Further, the VDD voltage connection line 333 may be composed of a firstVDD voltage connection line 334 and a second VDD voltage connection line335 constituting different layers and being electrically connected toeach other.

In this case, the first VDD voltage connection line 334, the sourceelectrode 217 a and drain electrode 217 b of the driving thin-filmtransistor 210 of the pixel may be made of the same material and mayconstitute the same layer. The second VDD voltage connection line 335and the gate electrode 214 of the driving thin-film transistor 210 ofthe pixel may be made of the same material and may constitute the samelayer.

For example, in order to connect the VDD voltage connection line 333 tothe second VDD voltage line 332, the first VDD voltage connection line334 and the second VDD voltage connection line 335 constitute differentlayers and are electrically connected to each other.

The VDD voltage connection line 333 electrically connects the first VDDvoltage line 331 and the second VDD voltage line 332 sandwiching thedisplay regions DA therebetween to each other. Thus, the first VDDvoltage connection line 334 and the second VDD voltage connection line335 constitute different layers so that the VDD voltage connection line333 does not form a short-circuit with various line connection pads andlines in a region between the first and second VDD voltage lines 331 and332.

Thus, the VDD voltage connection line 333 may be embodied as the firstVDD voltage connection line 334 in a region between the first VDDvoltage line 331 and the display region DA. When the VDD voltageconnection line 333 extends across the display region DA, the VDDvoltage connection line 333 may be embodied as the second VDD voltageconnection line 335. That is, the VDD voltage connection line 333changes from the first VDD voltage connection line 334 to the second VDDvoltage connection line 335.

That is, the first VDD voltage connection line 334 and the second VDDvoltage connection line 335 constitute different layers and areelectrically connected to each other via at least one contact-hole.

Then, the VDD voltage connection line 333 may be embodied as the firstVDD voltage connection line 334 which may be connected to the second VDDvoltage line 332, as shown in FIG. 12 , in a region between the displayregion DA and the second VDD voltage line 332.

In this case, the first VDD voltage connection line 334 and the secondVDD voltage line 332 may be electrically connected to each other via thesecond VDD voltage connection line 335 connected to the first VDDvoltage connection line 334 via at least one second VDD voltageconnection line contact-hole 335 h.

In addition, auxiliary lines 327 connected to the second VDD voltageline 332 via at least one contact-hole may be disposed in a region wherethe second VDD voltage line 332 does not overlap the data line 313 andVSS voltage connection line 323.

The auxiliary line 327 and the gate electrode 214 may be made of thesame material and may constitute the same layer.

The VDD voltage auxiliary line 327 may be connected to a rear face ofthe second VDD voltage line 332 to reduce an overall resistance of thesecond VDD voltage line 332.

FIG. 7 additionally shows a passivation-hole formed in the passivationlayer 218. FIG. 8 further shows a first connection electrode 351connecting the VSS voltage line connection pad 320 and the first VSSvoltage line 321 to each other, and a second connection electrode 352connecting the reference voltage line connection pad 340 and thereference voltage line 341 to each other.

The passivation layer 218 may be formed on the reference voltage lineconnection pad 340, the VDD voltage line connection pad 330, the VSSvoltage line connection pad 320, the reference voltage line 341, thefirst VSS voltage line 321, the second VSS voltage line 322, the firstVDD voltage line 331, and the second VDD voltage line 332. Thepassivation layer 218 may act as a planarization layer made of anorganic material layer such as PAC.

Further, the passivation layer 218 serves as an insulating layer. Thus,for electrical connection between the line connection pads and thelines, a passivation-hole, that is, a planarization-hole may be formedin portions of each line connection pad and each line.

The passivation-hole means not only a contact-hole, but also an openhole formed by partially removing the passivation layer 218 to secure acontact area as much as possible. Each line connection pad and each linemay be electrically connected to each other via the connectionelectrodes connected to each other via the passivation-hole.

In FIG. 7 , in order to clarify distinction between the layers, thepassivation layer 218 is not shown separately, but only a region wherethe passivation-hole is formed is shown in an emphasis manner.

A first passivation-hole 218 a is formed on the VSS voltage lineconnection pad 320 and the first VSS voltage line 321. The firstconnection electrode 351 electrically connects the VSS voltage lineconnection pad 320 and the first VSS voltage line 321 to each other viathe first passivation-hole 218 a, as shown in FIG. 8 and FIG. 14 .

In other words, in order to prevent a short circuit between the VSSvoltage line connection pad 320 and the first VSS voltage line 321 andthe first VDD voltage line 331 and the reference voltage line 341disposed between the VSS voltage line connection pad 320 and the firstVS S voltage line 321, a jumping connection structure of an electrode toconnect the VSS voltage line connection pad 320 and the first VSSvoltage line 321 to each other may be beneficial.

Therefore, according to an embodiment of the present disclosure, thepassivation layer 218 is formed on the first VDD voltage line 331 andthe reference voltage line 341. The first passivation-hole 218 a isformed on the VSS voltage line connection pad 320 and the first VSSvoltage line 321.

Thus, the jumping connection structure of the electrode may be formedusing the first connection electrode 351 which is formed on thepassivation layer 218 and whose one portion is connected to the VSSvoltage line connection pad 320 via one first passivation-hole 218 a andwhose an opposite portion is connected to the first VSS voltage line 321via an opposite first passivation-hole 218 a.

The first connection electrode 351 and the anode electrode as the firstelectrode 221 constituting the organic light-emitting element 220 may bemade of the same material and may constitute the same layer.

The first connection electrode 351 electrically connects the VSS voltageline connection pad 320 and the first VSS voltage line 321 to each otherand, to this end, is preferably formed to have a large area as much aspossible in order to reduce or minimize electrical resistance and toincrease or maximize uniformity of the resistance distribution.

Therefore, the first connection electrode 351 may be formed to extendover the first VDD voltage line 331, the reference voltage line 341, andthe first VSS voltage line 321, and thus may be formed to have anincreased area or a maximum area.

However, the first connection electrode 351 does not extend over allregions of the first VDD voltage line 331 and the reference voltage line341 and the first VSS voltage line 321. The first connection electrode351 does not extend over a partial region such as a region of the secondconnection electrode 352 as described later or a spacing region betweenthe first and second connection electrodes 351 and 352.

Further, in ordered to increase or maximize a contact area of the firstpassivation-hole 218 a with the VSS voltage line connection pad 320 andthe first VSS voltage line 321, the first passivation-hole 218 a mayhave a shape corresponding to the first VSS voltage line 321, that is, along bar shape (e.g., an elongated bar shape).

Further, at least one gas exhaust hole 355 may be formed in at least apartial region of the first connection electrode 351 as shown in FIG. 14.

The gas exhaust hole 355 serves to discharge unnecessary gases that maybe generated during a process of forming the transparent display panel300. Thus, when forming the gas exhaust hole 355 in the first connectionelectrode 351 having a large area, reliability of the transparentdisplay panel 300 may be further enhanced.

The bank layer 231 formed on the first connection electrode 351 has openregions defined therein corresponding to the gas exhaust holes 355 tosecure a passage of the gas exhaust hole 355. Each bank layer 231 maydefine a boundary between adjacent gas exhaust holes 355.

Further, a VSS voltage auxiliary line connection pad 326 may beadditionally disposed and may be electrically connected to the first VSSvoltage line 321 via the first connection electrode 351.

The VSS voltage auxiliary line connection pad 326 and the VSS voltageline connection pad 320 may be made of the same material and constitutethe same layer. However, the VSS voltage auxiliary line connection pad326 has an island form separated from the VSS voltage line connectionpad 320 and not connected to a separate line.

The first passivation-hole 218 a is formed on the VSS voltage auxiliaryline connection pad 326 such that the VSS voltage auxiliary lineconnection pad 326 is connected to the first connection electrode 351via the first passivation-hole 218 a, thereby increasing a total area ofthe first connection electrode 351, thereby reducing the overallresistance and making the resistance distribution more uniform.

In one example, the passivation layer 218 is formed on the referencevoltage line connection pad 340 and the reference voltage line 341. Thesecond connection electrode 352 electrically connects the referencevoltage line connection pad 340 and the reference voltage line 341 toeach other via a second passivation-hole 218 b as shown in FIG. 8 andFIG. 14 .

In order to prevent a short circuit between the reference voltage lineconnection pad 340 and the reference voltage line 341 and the first VDDvoltage line 331 between the reference voltage line connection pad 340and the reference voltage line 341, a jumping structure of an electrodefor connecting the reference voltage line connection pad 340 and thereference voltage line 341 to each other is required.

Therefore, according to an embodiment of the present disclosure, thepassivation layer 218 is formed on the first VDD voltage line 331, andthe second passivation-hole 218 b is formed on each of the referencevoltage line connection pad 340 and the reference voltage line 341, asshown in FIG. 7 .

Thus, the jumping connection structure of an electrode may be formedusing the second connection electrode 352 which is formed on thepassivation layer 218 and whose one portion is connected to thereference voltage line connection pad 340 via one secondpassivation-hole 218 b and whose an opposite portion is connects to thereference voltage line 341 via an opposite second passivation-hole 218b.

The second connection electrode 352 and the first connection electrode351 may be made of the same material and may constitute the same layerbut may be spaced apart from each other. Thus, the second connectionelectrode 352 may have an island shape.

Therefore, the second connection electrode 352 and the anode electrodeas the first electrode 221 constituting the organic light-emittingelement 220 of the pixel may be made of the same material and mayconstitute the same layer.

The second connection electrode 352 electrically connects the referencevoltage line connection pad 340 and the reference voltage line 341 toeach other and, to this end, is preferably formed to have a large areaas much as possible in order to reduce or minimize resistance thereofand increase or maximize uniformity of resistance distribution thereof.Further, the second passivation-hole 218 b is formed to have a largearea as much as possible to increase or maximize a contact area thereofwith the reference voltage line connection pad 340 and the referencevoltage line 341.

Further, at least one gas exhaust hole 355 may be formed in a partialregion of the second connection electrode 352 as in the first connectionelectrode 351.

In one example, a third passivation-hole 218 c may be formed on thesecond VSS voltage line 322, as shown in FIG. 7 . As shown in FIG. 8 , athird connection electrode 353 may be formed on the thirdpassivation-hole 218 c.

The third passivation-hole 218 c formed on the second VSS voltage line322 is intended for connecting the second VSS voltage line 322 and thethird connection electrode 353 to each other. The third connectionelectrode 353 is electrically connected to the second VSS voltage line322 via the third passivation-hole 218 c.

In order to reduce the resistance by increasing or maximizing thecontact area between the second VSS voltage line 322 and the thirdconnection electrode 353, the third passivation-hole 218 c may have abar shape corresponding to the second VSS voltage line 322.

Further, when forming the third connection electrode 353 at a lower endportion of the transparent display panel 300, an effect may occur that adifference between vertical levels of the lower end portion of thetransparent display panel 300 and an upper end portion of thetransparent display panel 300 in which the first connection electrode351 and the second connection electrode 352 may be removed.

The third connection electrode 353, the first connection electrode 351and the second connection electrode may be made of the same material andmay constitute the same layer but may be spaced apart from each other.Thus, the third connection electrode 353 is formed to have an islandshape.

Accordingly, the third connection electrode 353 and the anode electrodeas the first electrode 221 constituting the organic light-emittingelement 220 of the pixel may be made of the same material and mayconstitute the same layer.

The bank layer 231 may be formed on the first connection electrode 351,the second connection electrode 352 and the third connection electrode353. As shown in FIG. 9 , the bank layer 231 may form a dam 380 disposedin the non-display region NDA to surround the display region DA. The dam380 may include at least one dam 380 as patterned. When the dam 380 isformed on the first substrate 200, the dam 380 may serve to prevent anencapsulating material used to form the encapsulating layer 250 fromflowing to an outside.

The dam 380 may be disposed in the non-display region NDA, and may bedisposed to surround the lighting tester 375 and the first VDD voltageline 331 disposed in the non-display region NDA.

In one example, a fourth connection electrode 354 is formed on the banklayer 231, and is connected to the cathode electrode as the secondelectrode 225 of the pixel. The fourth connection electrode 354 iselectrically connected to the VSS voltage line to apply a VSS voltage tothe cathode electrode of the pixel. In this case, the cathode electrodeand the fourth connection electrode 354 may be formed integrally witheach other.

One end of the fourth connection electrode 354 is electrically connectedto the first connection electrode 351 to which the VSS voltage isapplied, while the other end of the fourth connection electrode 354 iselectrically connected to the third connection electrode 353, thereby toapply the VSS voltage to the cathode electrode.

As shown in FIG. 9 , FIG. 10 and FIG. 16 , the bank layer 231 is formedon the first connection electrode 351. A first bank-hole 231 a is formedon the first connection electrode 351 and is formed by removing apartial region of the bank layer 231, thereby to expose the firstconnection electrode 351 to an outside. Thus, the first connectionelectrode 351 may be electrically connected to one end of the fourthconnection electrode 354 via the first bank-hole 231 a.

When the VSS voltage is applied to the fourth connection electrode 354,the fourth connection electrode 354 is not directly connected to thefirst VSS voltage line 321, but the fourth connection electrode 354 isconnected thereto via the first connection electrode 351 made of a samematerial as an anode electrode, thereby to reduce an electricalresistance.

To increase or maximize the contact area between the first connectionelectrode 351 and the fourth connection electrode 354, the firstbank-hole 231 a of the bank layer 231 on the first connection electrode351 may be formed in a bar shape as in the reference voltage line 341.

Further, the first bank-hole 231 a may be formed in a correspondingmanner to the reference voltage line 341 or the first VSS voltage line321. For example, in some cases, the first bank-hole 231 a may overlapwith either the reference voltage line 341 or the first VSS voltage line321.

For example, when the first bank-hole 231 a is formed on a separatecircuit region such as an ESD protection circuit region 371, there maybe a problem that the bank-hole is formed in a region where a flatnessis poor.

Further, when the first bank-hole 231 a is formed on a line far awayfrom the first VSS voltage line 321 such as the first VDD voltage line331, a current path of the fourth connection electrode 354 which iselectrically connected to the first VSS voltage line 321 via the firstbank-hole 231 a becomes longer. Thus, the resistance increasescorrespondingly.

For example, when a length of a connection to the fourth connectionelectrode 354 as the cathode electrode of the high resistance ratherthan the anode electrode of the low resistance is larger, the overallresistance may be greater.

Thus, according to an embodiment of the present disclosure, the firstbank-hole 231 a is preferably formed on the reference voltage line 341or the first VSS voltage line 321.

When the first bank-hole 231 a is formed on the reference voltage line341, an inclined face of the hole may be removed to obtain a highflatness, thereby to reduce resistance variation than when a bank-holeis formed in a portion of the bank layer 231 on which no line is formed.

Further, when the first bank-hole 231 a is formed on the first VSSvoltage line 321, a length of a connection between the fourth connectionelectrode 354 and the first VSS voltage line 321 becomes smaller,thereby reducing the resistance.

As shown in FIG. 9 and FIG. 10 , a second bank-hole 231 b formed byremoving a partial region of bank layer 231 is formed in a portion ofthe bank layer 231 on the third connection electrode 353 electricallyconnected to the second VSS voltage line 322, thereby to electricallyconnect an opposite portion of the fourth connection electrode 354 tothe third connection electrode 353.

In this case, the second bank-hole 231 b is formed to correspond to athird passivation-hole 218 c on the second VSS voltage line 322. Thus,while the second VSS voltage line 322, the third connection electrode353 and the fourth connection electrode 354 are in a stacked state, theyelectrically contact each other at the same position. For example, insome cases, the second bank-hole 231 b overlaps with a thirdpassivation-hole 218 c on the second VSS voltage line 322.

In addition, the second VSS voltage line 322 is not directly connectedto the cathode electrode, but is connected thereto via the thirdconnection electrode 353 as a low-resistance anode electrode, thereby toreduce resistance.

Due to the connection structure of the fourth connection electrode 354,the VSS voltage may be applied to the fourth connection electrode 354.Thus, the VSS voltage may be applied to the cathode electrode of theorganic light-emitting element 220. That is, the VSS voltage appliedfrom the VSS voltage line connection pad 320 may be applied to thefourth connection electrode 354 via the first VSS voltage line 321 andthe first connection electrode 351.

The fourth connection electrode 354 may extend across an entirety of thedisplay region DA including the first VDD voltage line 331, thereference voltage line 341, the first VSS voltage line 321, the secondVDD voltage line 332 and the second VSS voltage line 322.

For example, as shown in FIG. 15 , the cathode electrode may extendacross an entirety of the display region DA including the second VDDvoltage line 332 and the second VSS voltage line 322, and may besurrounded with the dam 380.

In one example, the GIP circuit region 360 includes a GIP division block361 and a clock signal line region 363, as shown in FIG. 17 .

The GIP division block 361 includes at least one GIP division block thatdivides the gate lines GL into multiple blocks and drives each of themultiple blocks in each of multiple display driving periods. The clocksignal line region 363 may include at least one clock signal lines tocontrol nodes of the GIP circuit region 360.

The GIP division block 361 and the clock signal line region 363 may bealternately arranged in a direction away from the display region DA.

Specifically, non-transparent and thick VSS voltage lines may be omittedin left and right portions of the non-display region NDA left and rightto the display region DA. Thus, the GIP circuit region 360 may occupy aregion increased by the omitted area.

Therefore, the GIP division block 361 and the clock signal line region363 constituting the GIP circuit region 360 may be arranged in anon-compacted manner. Thus, a transparent region may be secured even inthe GIP circuit region 360.

For example, in a case where a space of the GIP circuit region 360 isnarrow, the GIP division block 361 and the clock signal line region 363must be arranged in a very dense manner to increase or maximize spaceutilization. Thus, it is difficult to secure a separate transparentregion In the GIP circuit region 360.

To the contrary, when the space of the GIP circuit region 360 increasesas in one embodiment of the present disclosure, the GIP division block361 having a non-transparent region at a larger amount and the clocksignal line region 363 having a transparent region at a larger amountmay be alternately arranged in the GIP circuit region 360 in adistinguished manner. Thus, the transparent region may be secured to themaximum even in the GIP circuit region 360.

In other words, according to one embodiment of the present disclosure,the VSS voltage line is omitted in one side region of the non-displayregion NDA out of the display region DA where the GIP circuit region 360is disposed, as shown in FIG. 17 and FIG. 18 . Thus, reduction of atransparent region due to the non-transparent VSS voltage line may bereduced or minimized.

Therefore, the lighting tester 375 may be disposed between the dam 380and the GIP circuit region 360, but the VSS voltage line may not bedisposed between the dam 380 and the GIP circuit region 360.

A transparent display device should be capable of displaying imageinformation to be displayed while having the same properties as those ofa transparent glass substrate. A transparent display device having suchcharacteristics may be configured as a complex transparent displaydevice in which the display information and a spatial situation behindthe transparent display device overlap with each other. Representativeexamples thereof include a head-up-display (HUD) used in airplanes andautomobiles.

The head-up-display used in a vehicle as shown in FIG. 19 is mounted ona windshield of the vehicle to display various driving information to adriver while allowing the driver's front view to be secured.

Therefore, in the head-up-display, high visibility of displayinformation is required. When a haze value is high, visibility ofdisplay information is not good. Thus, it is important to make the hazevalue as low as possible.

The haze is related to clarity of an object (or objects) seen throughthe transparent display device. Therefore, in a transparent displaydevice having a high transmittance but a high haze value, there is aproblem in that a driver sees the object in a blurry manner, and thusvisibility of display information is deteriorated. Occurrence of thehaze in the transparent display device may be attributed to thefollowing light characteristics.

FIG. 20A shows a long-distance diffraction pattern by a single slit.FIG. 20B is an illustration of a diffraction effect in a single slit.

Diffraction of a wave refers to a phenomenon in which a wave front isbent when the wave encounters an obstacle or a slit. In diffractionusing a single slit, a surface wave of a certain wavelength havingexited the slit forms a myriad of spherical waves.

In this regard, light may be treated as a wave in that a diffractionphenomenon occurs in a slit experiment using light as shown in FIG. 20A.As the light passes through the slit, diffraction appears in the sameway as the surface wave. However, a myriad of new spherical wavesinterfere with each other, resulting in occurrence of contrastingdiffraction patterns.

FIG. 20B shows Fraunhoffer diffraction in which a diffraction pattern isviewed at a long distance from a diffracting object. The Fraunhofferdiffraction occurs when all rays are considered as parallel rays, andthe diffraction pattern is the same regardless of the distance.

A condition under which the Fraunhoffer diffraction occurs in a singleslit may be calculated as follows.

When a difference between paths of two light beams traveling at an edgeand a center of the slit respectively is r1−r2,

${r\; 1} - {r\; 2{= {\frac{a}{2}\sin{\theta.}}}}$In the connection, a m-th offset interference condition in which anoffset interference occurs is

${{\frac{a}{2}\sin\theta} = {\pm \frac{m\lambda}{2}}}.$Since θ is usually much smaller than 1, a darkened point corresponds toa point away

$\theta = {{{\pm \frac{m\lambda}{a}}\mspace{14mu}{or}\mspace{14mu}{ym}} = {{\pm \frac{m\lambda}{a}}R}}$from the center.

FIG. 21A to FIG. 21D shows results of a double slit experiment for aparticle, a wave, light, and an electron, respectively.

When particles pass through a double slit, a distribution of particleshitting a screen appears as a simple sum of single distributions of theparticles passing through a single slit as shown in FIG. 21A.

That is, in this case, a bright band appears on a portion of the screencorresponding not to a center of the screen but to a slit position. Whenthe wave passes through the double slit, the brightest band appears atthe center of the screen, as shown in FIG. 21B. This allow knowingwhether interference occurs. Since the particles do not interfere witheach other, a distribution of particles is strong at a position wherethey may pass through the slit in a best manner.

In one example, when the light passes through the double slit as shownin FIG. 21C, an interference pattern resulting from a fact that theparticle property thereof disappears and the wave passes therethroughoccurs. Electron is generally considered to be a particle. However, whenan electron accelerated at a high speed passes through a double slit asshown in FIG. 21D, a result appears as the same result as that of adouble slit experiment of the wave.

That is, it may be seen that even when the particles pass through thedouble slit at a sufficiently high speed, the same interference as thatoccurring in the wave occurs. As a result, it may be seen that light hasthe wave-particle duality in that light is a wave generated by particlesas photons that is sufficiently fast.

In this way, light has the properties of waves and particles at the sametime. Thus, when the light encounters a slit having a periodic pattern,overlapping and offsetting occur, resulting in periodic diffraction.Consequently, the diffraction phenomenon due to the wave-particleduality of light may vary depending on a shape of the transmissiveregion which acts as a slit in the transparent display device.

For example, FIG. 22 shows an arrangement of transmissive regions havinga typical quadrangle shape in a transparent display device.

Multiple transmissive regions TAij in which i is a row number, and j isa column number (i and j are natural numbers) are arranged in a matrixtype. Thus, the transmissive regions in a first row include TA11, TA12,TA13 . . . , the transmissive regions in a second row include TA21,TA22, TA23 . . . , and the transmissive regions in a third row includeTA31, TA32, TA33 . . . . Similarly, the transmissive regions in a firstcolumn are TA11, TA21, TA31 . . . , the transmissive regions in a secondcolumn are TA12, TA22, TA32 . . . , and the transmissive regions in athird column are TA13, TA23, TA33 . . . .

In this case, each transmissive region has a rectangular shape havingall internal angles of 90 degrees. As a result, each of the transmissiveregions TA21 and TA23 adjacent to the transmissive region TA22 to thesame row has a vertical side facing and parallel to a vertical side ofthe transmissive region TA22.

Further, each of the transmissive regions TA12 and TA32 adjacent to thetransmissive region TA22 in the same column has a horizontal face facingand parallel to a horizontal side of the transmissive region TA22. Thatis, each of all sides of the transmissive region TA22 faces and isparallel to a corresponding side of each of adjacent transmissiveregions. The same principle may be equally applied to other transmissiveregions.

Since light transmits the transmissive regions, they may play the samerole as the slit illustrated in the double slit experiment above.Therefore, occurrence or non-occurrence, and an intensity of diffractionof light may vary depending on shapes and an arrangement structure ofthe transmissive regions.

Diffraction of light is caused by periodic repetition of linesconstituting the slit, and may be more clearly generated when adjacentlines constituting the slit have a periodicity in a parallel manner toeach other or when the slits are periodically arranged.

Therefore, in the transparent display device, when the transmissiveregions, each having the rectangular shape are arranged in a matrix typehaving regularity and periodicity in a parallel manner as shown in FIG.22 , the diffraction phenomenon of light may be clearly observed.

FIG. 23 shows the diffraction phenomenon of light generated when lightis incident onto a central region of a transparent display device havingthe transmissive region shape and the arrangement structure of thetransmissive regions as shown in FIG. 22 .

As may be seen in FIG. 23 , it may be seen that the diffractionphenomenon of light appears very clearly around the central region wherethe light is incident. As the diffraction phenomenon of light becomesmore apparent in the transparent display device, the haze alsoincreases. As a result, the clarity or visibility of the transparentdisplay device is reduced.

Therefore, there is a need for a new pixel structure having a shape of atransmissive region that may reduce or minimize the diffraction of lightcaused by periodic repetition of lines in the transmissive regions.Thus, the present disclosure provides a new pixel structure includingtransmissive regions having a new transmissive region shape as follows.A transparent display panel according to another embodiment according tothe present disclosure includes a substrate having a display regionincluding a plurality of light-emitting regions and a plurality oftransmissive regions, and a plurality of line regions disposed on thesubstrate and extending across the display region, wherein an outercontour of each of the transmissive regions is at least partiallycurved.

For example, in an embodiment of the present disclosure shown in FIG. 24, an outer contour of each of the transmissive regions may be partiallycurved. Specifically, the transmissive region TA22 has four outwardlyconvex sides corresponding to four sides of a dotted virtual rectangledrawn inside the transmissive region. The same feature may be applied toother transmissive regions.

Thus, mutually facing sides of the transmissive region TA22 and each oftransmissive regions TA21 and TA23 adjacent to the transmissive regionTA22 may not be parallel to each other. Further, mutually facing sidesof the transmissive region TA22 and each of transmissive regions TA12and TA32 adjacent to the transmissive region TA22 in the same column maynot be parallel to each other.

In another embodiment according to the present disclosure shown in FIG.25 , an outer contour of each of transmissive regions may be partiallycurved. Specifically, the transmissive region TA22 has six outwardlyconvex sides corresponding to six sides of a dotted virtual hexagondrawn inside the transmissive region. The same feature may be applied toother transmissive regions.

Thus, mutually facing sides of the transmissive region TA22 and each oftransmissive regions TA21 and TA23 adjacent to the transmissive regionTA22 may not be parallel to each other. Further, mutually facing sidesof the transmissive region TA22 and each of transmissive regions TA12and TA32 adjacent to the transmissive region TA22 in the same column maynot be parallel to each other.

In still another embodiment according to the present disclosure shown inFIG. 26 , an outer contour of each of transmissive regions has acircular shape. Specifically, the transmissive region TA22 is formed tohave a circular shape. The same feature may be applied to othertransmissive regions.

Thus, mutually facing sides of the transmissive region TA22 and each oftransmissive regions TA21 and TA23 adjacent to the transmissive regionTA22 may not be parallel to each other. Further, mutually facing sidesof the transmissive region TA22 and each of transmissive regions TA12and TA32 adjacent to the transmissive region TA22 in the same column maynot be parallel to each other.

In other words, all sides of the transmissive region TA22 in FIG. 24 toFIG. 26 may not be parallel to all sides of each of adjacenttransmissive regions thereto. The same features may be applied to othertransmissive regions.

Therefore, even when the transmissive regions, each having the shapeshown in FIG. 24 to FIG. 26 , are arranged in a matrix type, parallelregularity and periodicity of the transmissive regions acting as slitsare avoided, thereby reducing or minimizing the diffraction of light.

Further, in another embodiment according to the present disclosure, eachof transmissive regions may be formed in an elliptical shape. Due tothis elliptical shape, the parallel regularity and periodicity of thetransmissive regions that act as the slit as illustrated above may beavoided, thereby reducing or minimizing the diffraction of light as muchas possible.

Although FIG. 24 to FIG. 26 show that an entirety of the outer contourof each of the transmissive regions is curved by way of example, thepresent disclosure is not limited thereto. Even when only a portion ofthe contour of the transmissive region is curved, the parallelregularity and periodicity of the transmissive regions may be avoided,thereby reducing or minimizing the diffraction of light.

Therefore, in the transparent display panel including transmissiveregions, each having the outer contour being at least partially curved,diffraction of light may be reduced or minimized, thereby to reduce thehaze level. As a result, the clarity or visibility of the transparentdisplay device may be improved.

FIG. 27 shows the diffraction phenomenon of light generated when lightis shot onto a central region of a transparent display device having atransmissive region of a circular shape and an arrangement structure ofthe transmissive regions as shown in FIG. 26 . As may be seen in FIG. 27, substantially no diffraction of light is generated around the centralregion where light is incident.

Thus, non-occurrence of the diffraction of light in a transparentdisplay device having a transmissive region of a circular shape and anarrangement structure of the transmissive regions as shown in FIG. 26 isclearer, compared to FIG. 23 which shows the result when light isincident onto the central region of the transparent display devicehaving a conventional quadrangle transmissive region shape.

The diffraction of light is reduced or minimized, especially when thetransmissive region has a circular shape. Thus, in order to minimize thediffraction interference of light, it is desirable to form thetransmissive region to have a shape approximate to a circle as much aspossible. However, when the outer contour of the transmissive region isat least partially curved, as in the circular transmissive region, anarea of the transmissive region may be reduced. Thus, it may bedifficult to design a pixel including the light-emitting region and theline region.

Therefore, hereinafter, another embodiment according to the presentdisclosure capable of designing an optimized transmissive region and anoptimized light-emitting region while reducing or minimizing diffractioninterference of light is illustrated.

A transparent display panel according to another embodiment of thepresent disclosure includes a substrate including a display regionincluding a plurality of light-emitting regions and a plurality oftransmissive regions, and a plurality of line regions disposed on thesubstrate and extending across the display region, wherein each of thetransmissive region has a polygonal shape, and all internal angles ofthe polygon are obtuse.

For example, as shown in FIG. 28 , each of transmissive regions has apolygonal shape whose all internal angles are obtuse. That is, thepolygon having all internal angles being an obtuse angle include all ofpolygons having at least 5 sides. The polygon may include all of thesides of lengths equal to each other.

Specifically, in FIG. 28 , the transmissive region has a hexagon shape,and more specifically, a regular hexagon shape. This is one example. Asshown in FIG. 28 , mutually facing sides of the transmissive region TA22and each of transmissive regions TA21 and TA23 adjacent to thetransmissive region TA22 may not be parallel to each other. However,mutually facing sides of the transmissive region TA22 and each oftransmissive regions TA12 and TA32 adjacent to the transmissive regionTA22 in the same column may be parallel to each other.

Thus, when transmissive regions with hexagonal shapes are arranged asshown in FIG. 28 , mutually facing sides of transmissive regionsadjacent to each other in the same row may not be parallel to eachother. Thus, the parallel regularity and periodicity of the transmissiveregions are avoided, such that diffraction of light may be reduced orminimized as much as possible.

In other words, when mutually facing sides of transmissive regionsadjacent to each other in the same row and/or column are not parallel toeach other, diffraction of light may be reduced or minimized, comparedto when mutually facing sides of transmissive regions adjacent to eachother in the same row and/or column are parallel to each other.

In the hexagonal transmissive region shape shown in FIG. 28 , a lengthof each of mutually facing sides of transmissive regions adjacent toeach other in the same column is small. Thus, even when mutually facingsides of transmissive regions adjacent to each other in the same columnare parallel to each other, the diffraction phenomenon of light may bereduced.

Therefore, even when transmissive regions, each having the shape shownin FIG. 28 , are arranged in a matrix type in a transparent displaydevice, the parallel regularity and periodicity of the transmissiveregions acting as slits are avoided, such that diffraction of light maybe reduced or minimized as much as possible.

In another embodiment according to the present disclosure, as shown inFIG. 29 , each of the transmissive regions has an octagon shape,especially, a regular octagon shape having all internal angles being anobtuse angle. This is one example. The octagon as shown in FIG. 29 ismore approximate to a circle than the hexagon is, such that an effectsimilar to that as achieved by the transmissive region having a circularshape that reduces or minimizes diffraction of light may be obtained bythe shape of FIG. 29 .

In the octagonal transmissive region shape shown in FIG. 29 , a lengthof each of mutually facing sides of transmissive regions adjacent toeach other in the same column is small. Thus, even when mutually facingsides of transmissive regions adjacent to each other in the same columnare parallel to each other, the diffraction phenomenon of light may bereduced.

Therefore, even when transmissive regions, each having the shape shownin FIG. 29 , are arranged in a matrix type in a transparent displaydevice, the parallel regularity and periodicity of the transmissiveregions acting as slits are avoided, such that diffraction of light maybe reduced or minimized as much as possible.

That is, a transmissive region of a polygonal shape in which allinternal angles are obtuse, in particular, a transmissive region havinga regular polygonal shape in which all internal angles are obtuse has ashape more approximate to a circle, thereby reducing or minimizingdiffraction of light.

Further, an area of a transmissive region of a polygonal shape in whichall internal angles are obtuse may be larger than an area of the curvedor circular shaped transmissive region. Thus, when using a transmissiveregion of a polygonal shape in which all internal angles are obtuse, thepixel design and the line region design may be easier than that whenusing the curved or circular shaped transmissive region.

Therefore, a transparent display panel including a transmissive regionhaving a polygonal shape in which all internal angles are obtuse maysecure a maximum transmission region with the reduced haze level and mayfacilitate the design of the pixel and the line region.

Hereinafter, the arrangement shape of the light-emitting regions and thetransmissive regions according to an embodiment of the presentdisclosure will be described in more detail, based on the embodiment inwhich the transmissive region has an octagon among the variousembodiments of the transmissive region shapes as exemplified above.

As shown in FIG. 30 , a transparent display panel according to anembodiment of the present disclosure includes a substrate having adisplay region including a plurality of light-emitting regions and aplurality of transmissive regions, and line regions disposed on thesubstrate while extending across the display region. In this case, thetransmissive region has a polygonal shape in which all internal anglesare obtuse.

The transparent display panel may be composed of a transmission regionincluding a plurality of transmissive regions TA through which light istransmitted, and a non-transmission region NTA through which light isnot transmitted. In the transmission region, a plurality of transmissiveregions TA are arranged in a matrix composed of a plurality of rows oftransmissive regions and a plurality of columns of transmissive regions.

In this case, a plurality of transmissive regions TA arranged in thesame row may be referred to as one transmissive region row. For example,one transmissive region row may indicate the transmissive regionsrunning horizontally (e.g., along the x-axis). A plurality oftransmissive regions arranged in the same column may be referred to asone transmissive region column. For example, one transmissive regioncolumn may indicate the transmissive regions running vertically (e.g.,up and down or along the y-axis). In the connection, the row directionrefers to a horizontal direction of the substrate and coincides with theX-axis direction. The column direction is defined as the verticaldirection of the substrate coinciding with the Y-axis direction.

The non-transmissive region NTA may include a light-emitting region inwhich light is emitted and a non-light-emitting region in which light isnot emitted. The light-emitting region refers to a region in which alight-emitting region EA of a sub-pixel is disposed. Thenon-light-emitting region may contain a plurality of line regions CLA,each extending in the vertical direction of the substrate.

In this case, the plurality of line regions are column line regionsCLA1, CLA2, CLA3, CLA4 . . . , each extending in a column direction. Theplurality of line regions contains data lines and various voltage linesextending in the column direction. Further, a pixel circuit region PCAconnected to the light-emitting region of each sub-pixel may be disposedin the non-light-emitting region.

The pixel circuit region PCA may be disposed under the light-emittingregion EA and may be aligned with the light-emitting region EA. The PCApartially overlaps the light-emitting region EA and the non-overlappingregion of the PCA region may be contained in the non-light-emittingregion.

In addition, the line region CLA is placed in a non-light-emittingregion. However, when the light-emitting region EA partially overlapsthe line region CLA, a portion of the region CLA overlapping thelight-emitting region EA may act as a light-emitting region. A pluralityof transmissive regions (TAij, where i is the row number, and j is thecolumn number, i and j are natural numbers) may be arranged in matrixtype.

The transparent display panel of FIG. 30 is one example having asub-pixel arrangement structure of RG-BG, but the present disclosure isnot limited thereto. For example, a first color sub-pixel may be a redsub-pixel including a first color light-emitting region emitting redlight. A second color sub-pixel may be a green sub-pixel including asecond color light-emitting region emitting green light. A third colorsub-pixel may be a blue sub-pixel including a third color light-emittingregion emitting blue light. However, the present disclosure is notlimited thereto.

The first color sub-pixel Rij_SP includes a first color light-emittingregion Rij and a first color pixel circuit region Rij_CA that iselectrically connected to the first color light-emitting region Rij tocontrol light emission from the first color light-emitting region Rij.The first color pixel circuit region Rij_CA may be disposed under thefirst color light-emitting region Rij while partially overlappingtherewith. Thus, at least a partial region of the first color pixelcircuit region Rij_CA does not overlap with the first colorlight-emitting region Rij, and thus may be exposed to an outside.

In this case, a portion of the first color pixel circuit region Rij_CAas exposed to the outside may be positionally biased relative to thefirst color light-emitting region Rij, for example, may be biased to aright side to the first color light-emitting region Rij. Thus, it ispossible to more efficiently arrange the emitting region and the pixelcircuit region in an entire pixel arrangement structure.

In the partial region of the first color pixel circuit region Rij_CA asexposed to the outside, a first color sub-pixel contact-hole Rij_H thatelectrically connects the first color light-emitting region Rij and thefirst color pixel circuit region Rij_CA to each other may be formed.

Further, each of the second color sub-pixel Gij_SP and the third colorsub-pixel Bij_SP may be configured in the same manner as the first colorsub-pixel Rij_SP as exemplified above in terms of the light-emittingregion, the pixel circuit region, the sub-pixel contact-hole, etc. Thus,additional overlapping descriptions thereof will be omitted.

The first color sub-pixel is placed between adjacent rows of thetransmissive regions. For example, first color sub-pixels R11_SP,R12_SP, and R13_SP are disposed between the transmissive regions TA11,TA12, and TA13 in the first row and the transmissive regions TA21, TA22,and TA23 in the second row, respectively. Thus, the first colorlight-emitting regions R11, R12, and R13 may be disposed between thetransmissive regions TA11, TA12, and TA13 in the first row and thetransmissive regions TA21, TA22, and TA23 in the second row,respectively.

The first color sub-pixel is disposed between the second color sub-pixeland the third color sub-pixel. Thus, the first color light-emittingregion is disposed between the second color light-emitting region andthe third color light-emitting region.

Further, the first color sub-pixel is disposed between adjacent lineregion CLAs among the plurality of line regions CLA arranged in thevertical direction of the substrate and does not overlap with the lineregions CLA. The second color sub-pixel and the third color sub-pixelare disposed on the line region CLA and partially overlap the lineregion CLA.

For example, the second color sub-pixels G12_SP and G14_SP in the samerow as the first color sub-pixels R11_SP, R12_SP, and R13_SP among thesecond color sub-pixels at least partially overlap the second columnline region CLA2 and the fourth column line region CLA4, respectively.The second color sub-pixels G21_SP and G23_SP in the same row as thefirst color sub-pixels R21_SP, R22_SP, and R23_SP at least partiallyoverlap the first column line region CLA1 and the third column lineregion CLA3, respectively.

The third color sub-pixels B11_SP and B13_SP in the same row as thefirst color sub-pixels R11_SP, R12_SP, and R13_SP among the third colorsub-pixels at least partially overlap the first column line region CLA1and the third column line region CLA3, respectively. The third colorsub-pixels B22_SP and B24_SP in the same row as the first colorsub-pixels R21_SP, R22_SP, and R23_SP at least partially overlap thesecond column line region CLA2 and the fourth column line region CLA4,respectively.

In other words, as in a configuration in which the second colorsub-pixel B11_SP and the third color sub-pixel G21_SP are spaced apartin the column direction and disposed on the first column line regionCLA1, the second color sub-pixel and the third color sub-pixel aredisposed on one column line region and are alternately arranged in thecolumn direction.

Further, as in a configuration in which the second color sub-pixelB11_SP and the third color sub-pixel G12_SP in the same row are disposedon the first column line region CLA1 and the second column line regionCLA2 adjacent thereto respectively, the second color sub-pixel and thethird color sub-pixel are alternately arranged in the row direction andare disposed on column line regions adjacent to each other in the rowdirection respectively.

Therefore, the first color sub-pixel R11_SP, the second color sub-pixelG12_SP, the first color sub-pixel R12_SP, and the third color sub-pixelB13_SP are sequentially arranged in the first row. In the second rowadjacent to the first row, the first color sub-pixel R21_SP, the thirdcolor sub-pixel B22_SP, the first color sub-pixel R22_SP, and the secondcolor sub-pixel G23_SP are sequentially arranged to correspond to theabove pattern.

Therefore, the second color sub-pixel G12_SP, the first color sub-pixelR12_SP, and the third color sub-pixel B13_SP consecutively arranged inthe first row, and the third color sub-pixel B22_SP, the first colorsub-pixel R22_SP, and the second color sub-pixel G23_SP arranged in thesecond row surround the transmissive region TA22. When using thisarrangement shape as a basic unit, a plurality of units are arranged ina matrix manner in the display region.

That is, in the transmissive region according to an embodiment of thepresent disclosure, when the above-described basic unit is defined asone pixel, a single transmissive region is not divided into two or morein a single pixel, thereby to effectively suppress increase in the haze.

In this regard, the variation in the haze value based on the shape ofthe transmissive region and based on the division or non-division of thetransmissive region may be identified based on FIG. 31 and FIG. 32 .Specifically, FIG. 31A shows a configuration in which the transmissiveregion has a quadrangle shape, and three transmissive regions correspondto one pixel. FIG. 31B shows a configuration in which the transmissiveregion has a quadrangle shape, and two transmissive regions correspondto one pixel. FIG. 31C shows a configuration in which one transmissiveregion corresponds to one pixel while the transmissive region has acircular shape as in one embodiment of the present disclosure.

All of FIG. 31A to FIG. 31C are experiment results based on 145 ppi(pixels per inch). In FIG. 31A, a haze value of 2.76% was measured. InFIG. 31B, a haze value of 2.03% was measured. Therefore, it may be seenthat the haze value decreases by 26.4% as the number of transmissiveregions corresponding to one pixel decreases from three to two.

In FIG. 31C, a haze value of 1.33% was measured. Therefore, in FIG. 31C,the haze value decreased by 34.5% compared to that of FIG. 31B. Thus, itmay be clearly seen that as the number of transmissive regions decreasedfrom 2 to 1, and the transmissive region has the circular shape, thehaze value further decreases.

FIG. 32 shows a graph of the haze value when ppi is 200 ppi, 100 ppi,and 145 ppi respectively, and when the transmissive region has aquadrangle shape, and the number of transmissive regions correspondingto one pixel is 3 (A), when the transmissive region has a quadrangleshape, and the number of transmissive regions corresponding to one pixelis 2 (B), and when a circular transmissive region is provided, and thenumber of transmissive regions corresponding to one pixel is 1 (C).

As may be seen from the graph result value in FIG. 32 that in theconfiguration C in which a circular transmissive region is disposed, butthe number of transmissive regions corresponding to one pixel is 1, thehaze value is reduced or minimized for all ppi.

The first color light-emitting region, the second color light-emittingregion and the third color light-emitting region are arranged tocorrespond to the first color sub-pixel, the second color sub-pixel andthe third color sub-pixel, respectively. Thus, the light-emittingregions are arranged in the same manner as the arrangement structure ofthe sub-pixels as illustrated above.

As shown in FIG. 30 , the transmissive region has an octagonal shape.The first color light-emitting region has a rectangular shape. In thiscase, the shape of the first color light-emitting region is formed so asbe surrounded by the bank layer 231 as shown in FIG. 34. Specifically,in the first color light-emitting region, the bank layer 231 may beremoved to be opened.

Further, each of the second color light-emitting region and the thirdcolor light-emitting region may have a polygonal shape, for example, ahexagon. A shape of each of the second color light-emitting region andthe third color light-emitting region is formed so as be surrounded bythe bank layer 231. Specifically, in each of the second and third colorlight-emitting regions, the bank layer 231 may be removed to be opened.

An area of one first color light-emitting region may be smaller than anarea of each of one second color light-emitting region and one thirdcolor light-emitting region. Specifically, since the red light-emittingregion has a longer lifespan than that of each of the green and bluelight-emitting regions, the former has better lifespan reliability andlight-emitting efficiency. Therefore, it is desirable to form the redlight-emitting region to have a smaller area than that of each of thegreen and blue light-emitting regions. For example, the first colorlight-emitting region, the second color light-emitting region, and thethird color light-emitting region may be formed at an area ratio ofapproximately 1:1.8:1.8.

Each of the second color light-emitting region and the third colorlight-emitting region may be disposed on the corresponding line regionand may at least partially overlap therewith. In this case, each of thesecond color light-emitting region and the third color light-emittingregion may be arranged to be symmetrical around each corresponding lineregion. Due to this arrangement structure, the transparent display panelaccording to an embodiment of the present disclosure may have a pixelarrangement structure that may make the most of a light-emitting areaefficiently.

In another embodiment of the present disclosure, as shown in FIG. 33 ,each of the second color sub-pixel and the third color sub-pixel mayinclude a light-emitting region further extending along the line regionin the column direction of the line region.

In order to secure the light-emitting region as much as possible, asshown in FIG. 33 , for example, the third color sub-pixel B11_SP and thesecond color sub-pixel G21_SP arranged in the column direction of thefirst line region CLA1 expand such that a spacing therebetween islarger.

Preferably, the third color sub-pixel B11_SP and the second colorsub-pixel G21_SP arranged in the column direction of the first lineregion CLA1 may be further extended to an extent such that distal endsof the two sub-pixels abut each other. However, the distal ends thereofmay have a predefined separation space therebetween considering aprocess margin.

In particular, when the second electrode of the organic light-emittingdiode, for example, the cathode electrode is made of a metal such as Aghaving a low sheet resistance, a separate contact structure is notrequired to lower the resistance of the cathode electrode. Thus, asshown in FIG. 33 , the area of each of the color sub-pixels may beexpanded as much as possible on the line region.

FIG. 34 and FIG. 35 show cross-sections of a I-I′ region and a J-J′region in FIG. 30 , respectively. FIG. 34 is a cross-sectional view of afirst color sub-pixel region. Specifically, the passivation layer 218 asa planarization layer is disposed on the first color pixel circuitregion R_PCA. The first electrode 221 of the organic light-emittingdiode 220, for example, an anode electrode, is formed on the passivationlayer 218.

The bank layer 231 is formed on the first electrode 221. In order toexpose a portion of the first electrode 221 corresponding to thelight-emitting region to the outside, a portion of the bank layer 231corresponding to the light-emitting region is removed and thus the banklayer is patterned. That is, the bank layer 231 may serve as a boundarythat defines the light-emitting region, thereby determining a shape ofthe light-emitting region, and may also serve as a boundary between thesub-pixel and the transmissive region.

The shape of the first electrode 221 is determined based on the shapeinto which the bank layer 231 is patterned. In order to increase ormaximize the transmittance and the light-emitting region, it isdesirable to form the bank layer to have a minimum width allowable in amask process for forming the bank layer 231.

On and over the first electrode 221, the organic light-emitting layer223 is formed to cover the bank layer 231. The second electrode 225, forexample, a cathode electrode, is formed on the organic light-emittinglayer 223. As the organic light-emitting layer 223 and the secondelectrode 225 are stacked on the first electrode 221 in an overlappingmanner to form the organic light-emitting diode 220, a region of thefirst electrode 221 exposed to an outside through an open region in thebank layer 231 may act as the light-emitting region.

The encapsulating layer 250 may be formed on the second electrode 225. Acolor filter CF may be formed on the encapsulating layer 250. The colorfilter CF may have the same color as a corresponding light-emittingregion. A first color filter R_CF corresponding to the first colorsub-pixel R_SP may have the same color as the first color.

When using the color filter CF, it is possible to reduce reflectance andincrease the color purity of RGB color. The color filter CF may extendto a boundary between the transmissive region TA and the light-emittingregion EA and thus may be formed in the non-transmissive region NTA.Therefore, a region where the color filter CF is formed may be definedas the light-emitting region.

The top substrate as the second substrate 270 may be adhered onto thecolor filter CF. Further, to prevent damage to the organic film layerwhich is vulnerable to high temperatures, the top substrate may bedisposed on the color filter CF using a COE (color-filter on encap)approach in which a low-temperature color filter process is performed onthe substrate without a bonding process.

In one example, FIG. 35 is a cross-sectional view of a border regionbetween the first color sub-pixel R_SP and the second color sub-pixelG_SP.

The passivation layer 218 as the planarization layer is disposed on thepixel circuit region PCA, specifically, the first color pixel circuitregion R_PCA and the second color pixel circuit region G_PCA. The firstelectrode 221 of the organic light-emitting diode 220, for example, ananode electrode is formed on the passivation layer 218.

The first electrodes 221 spaced apart from each other are respectivelyformed in the first color sub-pixel region and the second colorsub-pixel region. The bank layer 231 is formed on the first electrode221. In order to expose a portion of the first electrode 221corresponding to the light-emitting region to the outside, a portion ofthe bank layer 231 corresponding to the light-emitting region is removedand then the bank layer is patterned.

That is, the bank layer 231 may serve as a boundary between sub-pixelsadjacent to each other. The region corresponding to the bank layer 231may be a non-transmissive region NTA. On and over the first electrode221, the organic light-emitting layer 223 is formed to cover the banklayer 231. The second electrode 225 is formed on the organiclight-emitting layer 223.

As the organic light-emitting layer 223 and the second electrode 225 arestacked on the first electrode 221 in an overlapping manner to form theorganic light-emitting diode 220, the region of the first electrode 221exposed to the outside through the open region of the bank layer 231 maybe a light-emitting region.

The encapsulating layer 250 may be formed on the second electrode 225.The color filter CF may be formed on the encapsulating layer 250.

The first color filter R_CF corresponding to the first color sub-pixelR_SP may have the first color. The second color filter G_CFcorresponding to the second color sub-pixel G_SP may have the secondcolor.

Both of the first color filter R_CF and the second color filter G_CF maybe formed to be as wide as possible so that at least a partial regionthereof overlaps the bank layer 231.

In one example, the first color sub-pixel R_SP and the second colorsub-pixel G_SP are adjacent to each other. Thus, in order to reduce orminimize mixing of light beams of different colors adjacent to eachother and to clarify a boundary between different color light-emittingregions, a non-transparent black matrix may be disposed between thefirst color filter R_CF and the second color filter G_CF.

The black matrix may be formed in a pattern corresponding to the banklayer 231 forming the boundary, and may be formed to be narrower thanthe bank layer 231 and may be disposed inside the bank layer 231.

In one example, as shown in FIG. 36 , the substrate has a non-displayregion surrounding the display region. The non-display region mayinclude a dummy pixel pattern region DPA arranged to surround theoutermost portion of the display region. Specifically, the displayregion DA includes a plurality of sub-pixels SP. The dummy pixel patternregion DPA may include a plurality of dummy pixels or dummy sub-pixelsDSP (see FIG. 37 ).

The dummy pixel or dummy sub-pixel DSP is formed to reduce or minimize aprocess deviation and a side effect such as a loading effect that mayoccur during a manufacturing process of the transparent display device.The dummy pixel DSP may surround the sub-pixel to serve as a kind of abuffer area.

The dummy pixel DSP may have an organic light-emitting element layer anda circuit region such as a driving thin-film transistor as in thesub-pixel. However, a signal is not applied to each element layer andthe circuit region of the dummy pixel. Thus, a separate pixelcontact-hole SP_H that electrically connect the components thereof toeach other is not required. As a result, the organic light-emittingelement layer in the dummy pixel pattern region DPA does not emit light.For example, the circuit region such as the driving thin-film transistorof the dummy pixel may not work or operate to emit light.

The dummy pixel pattern region DPA surrounding the outermost portion ofthe display region DA may include a top row direction region and abottom row direction region above and below the display region DA, asshown in FIG. 37 . The dummy pixel pattern region DPA surrounding theoutermost portion of the display region DA may include a left columndirection region and a right column direction region left and right tothe display region DA as shown in FIG. 37 . The static electricity mayinvade the GIP regions left and right to the display region DA throughthe gate line. Thus, a left column direction region and a right columndirection region of the dummy pixel pattern region DPA may be thickerthan a top row direction region and a bottom row direction regionthereof. For example, as shown in FIG. 37 , the left column directionregion may have a width W₃ and the bottom row direction region may havea width W₄. In some embodiments, W₃ may be greater than W₄. However,other dimensions may be used in other embodiments according to thedisplay design.

Hereinafter, a transparent display panel according to another embodimentof the present disclosure to obtain the effects of the presentdisclosure as mentioned above without reducing transmittance of thedisplay region, and a transparent display device including the same willbe described in detail.

In a transparent display panel including a display region and anon-display region, as shown in FIG. 38 , the display region includes aplurality of light-emitting regions, a plurality of transmissiveregions, a plurality of line regions spaced apart from each other andarranged in one direction, and a plurality of pixel circuit regionselectrically connected to the light-emitting regions to drive thelight-emitting regions respectively.

First, each line region CLA extends in the vertical direction of thedisplay region. Alternate adjacent line regions CLA respectively includealternate adjacent VSS voltage connection line 323 and a VDD voltageconnection line 333.

In this case, the line region CLA including the VSS voltage connectionline 323 includes a plurality of reference voltage (Vref) connectionlines 343 arranged symmetrically around the VSS voltage connection line323, and a plurality of data (Vdata) lines 313 arranged symmetricallyaround the VSS voltage connection line 323.

In some embodiments, a plurality of reference voltage (Vref) connectionlines 343 are adjacently arranged around the VSS voltage connection line323, and a plurality of data (Vdata) lines 313 are also adjacentlyarranged around the VSS voltage connection line 323. Here, the pluralityof data (Vdata) lines 313 may be arranged adjacent to the outer side ofthe plurality of reference voltage (Vref) connection lines 343.

Further, line region CLA including the VDD voltage connection line 333includes a plurality of reference voltage connection lines 343 arrangedsymmetrically around the VDD voltage connection line 333, and aplurality of data lines 313 arranged symmetrically around VDD voltageconnection line 333.

In some embodiments, a plurality of reference voltage connection lines343 are adjacently arranged around the VDD voltage connection line 333,and a plurality of data lines 313 are also adjacently arranged aroundthe VDD voltage connection line 333. Here, the plurality of data lines313 may be arranged adjacent to the outer side of the plurality ofreference voltage connection lines 343.

For example, when the line region including the VDD voltage connectionline 333 is defined as a first column line region CLA1, the first columnline region CLA1 includes two reference voltage connection lines 343symmetrically arranged around the VDD voltage connection line 333, andtwo data lines 313 symmetrically arranged around the VDD voltageconnection line 333.

Further, a second column line region CLA2 immediately adjacent to thefirst column line region CLA1 includes the VSS voltage connection line323. In this case, the second column line region CLA2 includes tworeference voltage connection lines 343 arranged symmetrically around theVSS voltage connection line 323, and two data lines 313 arrangedsymmetrically around the VSS voltage connection line 323.

In accordance with the present disclosure, both of the VSS voltageconnection line 323 and the VDD voltage connection line 333 extendacross the display region. Thus, the non-transparent and thickconnection lines, especially, the VSS voltage connection lines may beremoved from the non-display region, such that a size of the transparentregion of the bezel may be increased or maximized and the bezel may beslimmed.

In particular, instead of disposing the non-transparent and thick VSSvoltage connection line in the non-display region, the VSS voltageconnection line is formed inside the display region and is divided intoa plurality of thin lines. Thus, the VSS voltage connection line mayconnect the upper first VSS voltage line and a lower second VSS voltageline sandwiching the display region therebetween to each other, therebyto reduce or minimize a decrease in transmittance of the display region.

In other words, when arranging the plurality of VSS voltage connectionlines and the plurality of VDD voltage connection lines together withthe data lines and the reference voltage connection lines in the displayregion, a decrease in transmittance of the display region may be reducedor minimized compared to a structure in which the VSS voltage connectionline is not formed in the display region.

The plurality of the light-emitting regions include a first second colorlight-emitting region Rij, a second color light-emitting region Gij, anda third color light-emitting region Bij. Each of the second colorlight-emitting region and the third color light-emitting region may atleast partially overlap each line region. Thus, the first colorlight-emitting regions may be placed between the line regions adjacentto each other. Each of the second color light-emitting region and thethird color light-emitting region may be arranged symmetrically aroundeach line region.

In one example, a first color sub-pixel Rij_SP includes a first colorlight-emitting region Rij, and a first color pixel circuit region RijPCA electrically connected to the first color light-emitting region Rijto drive the first color light-emitting region Rij to emit light. Thefirst color light-emitting region Rij and the first color pixel circuitregion Rij PCA may be electrically connected to each other via a firstcolor sub-pixel contact-hole Rij_H. Further, each of a second colorsub-pixel Gij_SP and a third color sub-pixel Bij_SP may be configured inthe same manner as the first color sub-pixel Rij_SP in terms of thelight-emitting region, the pixel circuit region, the sub-pixelcontact-hole, etc.

Therefore, a plurality of pixel circuit regions are arranged over thesubstrate and are electrically connected to the light-emitting regionsrespectively to drive the light-emitting regions. The pixel circuitregions include the first color pixel circuit region that iselectrically connected to the first color light-emitting region, thesecond color pixel circuit region electrically connected to the secondcolor light-emitting region, and the third color pixel circuit regionelectrically connected to the third color light-emitting region.

In this case, each of the plurality of pixel circuit regions may bearranged symmetrically with respect to each line region. Further, eachpixel circuit region may have a narrower shape as the pixel circuitregion extends away from a center of each line region. Specifically, thefirst color pixel circuit region may be arranged symmetrically to thesecond color pixel circuit region and the third color pixel circuitregion around a corresponding line region.

For example, the second color light-emitting region G12 may be arrangedsymmetrically around the second column line region CLA2. Further, thefirst color pixel circuit region R11_PCA and the second color pixelcircuit region G12_PCA may be arranged symmetrically to each otheraround the second column line region CLA2.

Specifically, the first color pixel circuit region R11_PCA has a shapethat becomes narrower as the first color pixel circuit region R11_PCAextends away from a center of the second column line region CLA2 in theleft direction. The second color pixel circuit region G12_PCA may have ashape that becomes narrower as the second color pixel circuit regionextends away from a center of the second column line region CLA2 in theright direction.

In this way, the first color pixel circuit region R12_PCA and the thirdcolor pixel circuit region B13_PCA may be arranged symmetrically to eachother around the third column line region CLA3.

Further, the first color pixel circuit region may overlap at leastpartial regions of the first color light-emitting region and the secondcolor light-emitting region, and may overlap at least partial regions ofthe first color light-emitting region and the third color light-emittingregion.

The second color pixel circuit region may overlap at least partialregions of the first color light-emitting region and the second colorlight-emitting region. The third color pixel circuit region may overlapat least partial regions of the first color light-emitting region andthe third color light-emitting region.

The arrangement form of the pixel circuit region is due to thearrangement form of the light-emitting region and the transmissiveregion. The light-emitting region become narrower as the region extendsaway from a center of a corresponding line region. Thus, the pixelcircuit region is disposed within the light-emitting region so as not tooverlap the transmissive region, thereby not to lower the transmittanceof the display region.

Therefore, according to the present disclosure, the VSS voltageconnection line and the VDD voltage connection line are alternatelyarranged in the adjacent line regions within the display region. Eachpixel circuit region connected to each light-emitting regioncorresponding to each color has a symmetrical structure. Thus, a newpixel arrangement structure capable of increasing or maximizing an areaof the transparent region of the bezel and reducing or minimizing thehaze value without reducing the transmittance of the display region maybe realized.

In one example, the pixel circuit region may include a driving thin-filmtransistor, a capacitor, and a plurality of switching thin-filmtransistors. That is, each of the first color pixel circuit region, thesecond color pixel circuit region, and the third color pixel circuitregion may include a driving thin-film transistor, a capacitor, and aplurality of switching thin-film transistors.

FIG. 39 shows a connection relationship between the line region and thepixel circuit region while enlarging a K-K′ region of FIG. 38 . FIG. 40shows a circuit diagram of the pixel circuit region.

One sub-pixel may include an organic light-emitting diode OLED, adriving thin-film transistor DR, a plurality of switching thin-filmtransistors T1, T2, T3, T4, and T5, and a capacitor Cst. The switchingthin-film transistors may include first to fifth switching thin-filmtransistors T1, T2, T3, T4, and T5.

The organic light-emitting diode OLED emits light using a currentsupplied via a driving thin-film transistor DR. An anode electrode ofthe organic light-emitting diode OLED may be connected to a drainelectrode of the driving thin-film transistor DR. A cathode electrodethereof may be connected to a VSS voltage connection line VSS to which aVSS power voltage is supplied. The VSS voltage connection line VSS mayact as a low-level voltage line to which a low-level power voltage issupplied.

The organic light-emitting diode OLED may include an anode electrode, anorganic light-emitting layer 223, and a cathode electrode. The organiclight-emitting layer 223 includes a hole injection layer (HIL), a holetransport layer (HTL), a light-emitting layer (EML), an electrontransport layer (ETL), and an electron injection layer (EIL). In theorganic light-emitting diode OLED, when voltage is applied to the anodeelectrode and the cathode electrode, holes and electrons are transferredto the light-emitting layer EML via the hole injection layer (HIL) andthe hole transport layer (HTL) and the electron injection layer (EIL)and the electron transport layer (ETL), respectively. The holes andelectrons are combined with each other in the light-emitting layer EMLto emit light.

The driving thin-film transistor DR is disposed between a VDD voltageconnection line VDD to which a VDD power voltage is supplied and theorganic light-emitting diode OLED. The driving thin-film transistor DRadjusts a current flowing from the VDD voltage connection line VDD tothe organic light-emitting diode OLED based on a voltage differencebetween the gate electrode and the source electrode.

The gate electrode of the driving thin-film transistor DR may beconnected to one electrode of the capacitor Cst and the second electrodeof the second switching thin-film transistor T2. The source electrode ofthe driving thin-film transistor DR may be connected to the anodeelectrode of the organic light-emitting diode OLED. The drain electrodeof the driving thin-film transistor DR may be connected to the VDDvoltage connection line VDD. The VDD voltage connection line VDD may actas a high-level voltage line to which a high-level power voltage issupplied.

The first switching thin-film transistor T1 is turned on based on afirst gate signal of a first scan line Scan1 to supply a voltage of thedata line Vdata to the other electrode of the capacitor Cst. The gateelectrode of the first switching thin-film transistor T1 may beconnected to the first scan line Scan1. The first electrode of the firstswitching thin-film transistor T1 may be connected to the data lineVdata. The second electrode of the first switching thin-film transistorT1 may be connected to the other electrode of the capacitor Cst.

The second switching thin-film transistor T2 is turned on based on asecond gate signal of a second scan line Scan2 to connect the gateelectrode and the drain electrode of the driving thin-film transistor DRto each other. The gate electrode of the second switching thin-filmtransistor T2 may be connected to the second scan line Scan2. The firstelectrode of the second switching thin-film transistor T2 may beconnected to the drain electrode of the driving thin-film transistor DR.The second electrode of the second switching thin-film transistor T2 maybe connected to the gate electrode of the driving thin-film transistorDR.

The third switching thin-film transistor T3 is turned on based on alight-emitting signal of a light-emitting line EM to initialize theother electrode of the capacitor Cst to a reference voltage. The gateelectrode of the third switching thin-film transistor T3 may beconnected to the light-emitting line EM. The first electrode of thethird switching thin-film transistor T3 may be connected to the otherelectrode of the capacitor Cst. The second electrode of the thirdswitching thin-film transistor T3 may be connected to a referencevoltage connection line Vref to which a reference voltage is supplied.

The fourth switching thin-film transistor T4 is turned on based on alight-emitting signal of the light-emitting line EM to connect the drainelectrode of the driving thin-film transistor DR and the anode electrodeof the organic light-emitting diode OLED to each other. The gateelectrode of the fourth switching thin-film transistor T4 may beconnected to the light-emitting line EM. The first electrode of thefourth switching thin-film transistor T4 may be connected to the drainelectrode of the driving thin-film transistor DR. The second electrodeof the fourth switching thin-film transistor T4 may be connected to theanode electrode of the organic light-emitting diode OLED.

The fifth switching thin-film transistor T5 is turned on based on asecond gate signal of the second scan line Scan2 to initialize the anodeelectrode of the organic light-emitting diode OLED to a referencevoltage. The gate electrode of the fifth switching thin-film transistorT5 may be connected to the second scan line Scan2. The first electrodeof the fifth switching thin-film transistor T5 may be connected to theanode electrode of the organic light-emitting diode OLED. The secondelectrode of the fifth switching thin-film transistor T5 may beconnected to the reference voltage connection line Vref.

The first electrode of each of the first to fifth switching thin-filmtransistors T1, T2, T3, T4, and T5 may act as a source electrode, andthe second electrode thereof may act as a drain electrode. However, thepresent disclosure is not limited thereto.

The capacitor Cst is formed between the gate electrode of the drivingthin-film transistor DR and the second electrode of the first switchingthin-film transistor T1. The capacitor Cst stores therein the voltagedifference between the voltage of the gate electrode of the drivingthin-film transistor DR and the voltage of the second electrode of thefirst switching thin-film transistor T1.

One electrode of the capacitor Cst may be connected to the gateelectrode of the driving thin-film transistor DR, and the secondelectrode of the second switching thin-film transistor T2. The otherelectrode of the capacitor Cst may be connected to the second electrodeof the first switching thin-film transistor T1 and the first electrodeof the third switching thin-film transistor T3.

In one embodiment of the present disclosure, an example in which each ofthe driving thin-film transistor DR and the first to fifth switchingthin-film transistors T1, T2, T3, T4, and T5 may be embodied as a P-typeMOSFET (Metal Oxide Semiconductor Field Effect) transistor has beendescribed. However, the present disclosure is limited thereto. Each ofthe driving thin-film transistor DR and the first to fifth switchingthin-film transistors T1, T2, T3, T4, and T5 may be embodied as a N-typeMOSFET (Metal Oxide Semiconductor Field Effect) transistor.

In one example, the driving thin-film transistor DR included in thepixel circuit region connected to the first color sub-pixel may at leastpartially overlap the second color light-emitting region of the secondcolor sub-pixel or the third color light-emitting region of the thirdcolor sub-pixel.

For example, as shown in FIG. 38 , the first color pixel circuit regionR11_PCA connected to the first color sub-pixel R11_SP may at leastpartially overlap the second color light-emitting region G12 of thesecond color sub-pixel G12_SP disposed on a right side to the firstcolor sub-pixel R11_SP. Specifically, the driving thin-film transistorDR included in the first color pixel circuit region R11_PCA may at leastpartially overlap the second color light-emitting region G12.

Further, the pixel circuit regions may be arranged symmetrically to eachother around one line region. In this case, one pixel circuit regionincluding a driving thin-film transistor DR driving a light-emittingregion at least partially overlapping the line region may be disposed onone side to the line region. The other pixel circuit region related to adifferent color from that of one pixel region and including a drivingthin-film transistor DR driving a light-emitting region between thecorresponding line region and a neighboring line region thereto may bedisposed on the other side to the line region.

That is, a driving thin-film transistor driving a light-emitting regionat least partially overlapping the line region may be disposed on oneside to the line region, while a driving thin-film transistor driving alight-emitting region between the line region and a neighboring lineregion thereto may be disposed on the other side to the line region.

For example, the line region CLA2 at least partially overlaps with thesecond color light-emitting region G12. The first color pixel circuitregion R11_PCA and the second color pixel circuit region G12_PCA may besymmetrically arranged to each other on one side to the line regionCLA2.

Thus, a driving thin-film transistor driving the light-emitting regionG12 at least partially overlapping the line region CLA2 may be disposedon one side to the line region CLA2. A driving thin-film transistordriving the light-emitting region R11 between the line region CLA2 andthe neighboring line region CLA1 thereto may be disposed on the otherside to the line region CLA2.

FIG. 41 to FIG. 43 show cross-sectional views of L-L′, M-M′, and N-N′regions in FIG. 38 , respectively.

As shown in FIG. 41 , a buffer layer 201, a gate insulating layer 213, afirst interlayer insulating layer 215, a second interlayer insulatinglayer 216 and a passivation layer 218 may be sequentially stacked overthe first substrate 200 in this order.

A line region including two reference voltage connection lines 343spaced apart from each other and arranged symmetrically around the VDDvoltage connection line 333 and two data lines 313 spaced apart fromeach other and arranged symmetrically around from the VDD voltageconnection line 333 may be disposed on the passivation layer 218. TheVDD voltage connection line 333 may be thicker than each of thereference voltage connection line 343 and the data line 313.

The planarization layer 219 may be disposed on the line region. Theorganic light-emitting element OLED 220 composed of the first electrode221, the organic light-emitting layer 223 and the second electrode 225may be disposed on the planarization layer 219. In this case, the banklayer 231 is formed between the first electrode 221 and the organiclight-emitting layer 223.

The encapsulating layer 250 is formed on the second electrode 225. Anadhesive layer 251 made of OCR (optical clear adhesive) may be formed onthe encapsulating layer 250. The color filter CF may be formed on theadhesive layer 251. The color filter CF may extend to a boundary betweenthe transmissive region TA and the light-emitting region EA such thatthe color filter CF may be formed in the non-transmissive region NTAregion. Therefore, a region where the color filter CF is formed may bedefined as a region corresponding to the light-emitting region. Onto thecolor filter CF, the top substrate as the second substrate 270 may beadhered.

As shown in FIG. 42 , a buffer layer 201, a gate insulating layer 213, afirst interlayer insulating layer 215, a second interlayer insulatinglayer 216 and a passivation layer 218 may be sequentially stacked overthe first substrate 200 in this order.

On the passivation layer 218, a line region including two referencevoltage connection lines 343 spaced apart from each other and arrangedsymmetrically around the VSS voltage connection line 323, and two datalines 341 spaced apart from each other and arranged symmetrically aroundthe VSS voltage connection line 323 may be disposed. In this case, theVSS voltage connection line 323 may be thicker than each of thereference voltage connection line 343 and the data line 341.

The planarization layer 219 may be disposed on the line region.Descriptions of subsequent components are the same as those made withreference to FIG. 41 . Thus, duplicate descriptions thereof will beomitted.

As shown in FIG. 43 , the buffer layer 201 is formed on the firstsubstrate 200. On the buffer layer 201, the driving thin-film transistor210 including an active layer 212, a source electrode 217 a, a drainelectrode 217 b, and a gate electrode 214, and the capacitor Cstcomposed of a first capacitor electrode 204 and a second capacitorelectrode 206 may be formed.

In this case, a gate insulating layer 213 may be formed between theactive layer 212 and the gate electrode 214 and the first capacitorelectrode 204. A first interlayer insulating layer 215 may be formed onthe gate electrode 214 and the first capacitor electrode 204, and thesecond capacitor electrode 206 may be formed on the first interlayerinsulating layer 215.

A second interlayer insulating layer 216 may be formed on the secondcapacitor electrode 206. The source electrode 217 a and the drainelectrode 217 b may be formed on the second interlayer insulating layer216. The passivation layer 218 may extend over the capacitor Cst and thedriving thin-film transistor 210. The planarization layer 219 may beformed on the passivation layer 218.

On the planarization layer 219, the organic light-emitting element 220including the first electrode 221, the organic light-emitting layer 223,and the second electrode 225 may be disposed. In this case, the banklayer 231 may be formed between the first electrode 221 and the organiclight-emitting layer 223.

The encapsulating layer 250 may be formed on the second electrode 225.The adhesive layer 251 made of OCR (optical clear adhesive) may beformed on the encapsulating layer 250. The color filter CF may be formedon the adhesive layer 251. Onto the color filter CF, the top substrateas the second substrate 270 may be adhered.

Hereinafter, another embodiment according to the present disclosure inwhich occurrence of non-uniformity of luminance in the display panel maybe reduced or minimized via introduction of an auxiliary electroderegion that may reduce an electrical resistance of the transparentelectrode will be described in detail.

As shown in FIG. 44 and FIG. 45 , the transparent display panel includesa display region and a non-display region. The display region includes aplurality of light-emitting regions, a plurality of transmissive regionsTA, a plurality of line regions CLA arranged in one direction and spacedapart from each other, and a plurality of auxiliary electrode regions AEarranged on the line region CLA.

The light-emitting region includes a first color light-emitting regionRij, a second color light-emitting region Gij, and a third colorlight-emitting region Bij. Each of the second color light-emittingregion Gij and the third color light-emitting region Bij may be disposedon a corresponding line region CLA.

The first color light-emitting region Rij may be disposed between thesecond color light-emitting region Gij and the third colorlight-emitting region Bij disposed on different line regions CLArespectively. An auxiliary electrode region AE may be disposed betweenthe second color light-emitting region Gij and the third colorlight-emitting region Bij on the same line region CLA. Thelight-emitting region may include an organic light-emitting element 220including a first electrode 221, an organic light-emitting layer 223 anda second electrode 225.

The first electrode 221 may include at least one of transparentconductive materials such as indium tin oxide (ITO), antimony tin oxide(ATO), and indium zinc oxide (IZO).

The organic light-emitting layer 223 has low diffraction propertiesbecause the organic light-emitting layer 223 is made of a low organicmaterial having a low step coverage. Thus, when the organiclight-emitting layer 223 is formed using a deposition process, theorganic light-emitting layer 223 may not penetrate well to a bottom faceof a step that is not exposed to an outside. Thus, the organiclight-emitting layer 223 may be formed using a vapor deposition processsuch as an evaporation method having excellent linearity for a vapordeposition target material.

The second electrode 225 may include at least one of transparentconductive materials such as indium tin oxide (ITO), Mg:Ag, Ca—Ag, andindium zinc oxide (IZO).

Particularly, the indium zinc oxide (IZO) is a material with a high stepcoverage and has high diffraction properties. Thus, when the secondelectrode 225 made of the IZO is formed via a vapor deposition process,the second electrode 225 may penetrate well to a lower face of a stepthat is not exposed to an outside.

Each of the plurality of line regions CLA extends in a verticaldirection of the display region. Alternately-arranged adjacent lineregions CLA includes a VSS voltage connection line 323 and a VDD voltageconnection line 333, respectively.

The auxiliary electrode region AE is disposed on the line region CLAincluding the VSS voltage connection line 323.

Specifically, the auxiliary electrode region AE includes an auxiliaryelectrode 221 a electrically connected to the VSS voltage connectionline 323, a partition wall 241 disposed on the auxiliary electrode 221a, wherein a width W₄ of a top face (or a top surface) of the partitionwall 241 is larger than a width W₅ of a bottom face (or a bottomsurface) thereof, and an electrode contact EC composed of a portion ofthe auxiliary electrode 221 a and a portion of the second electrode 225which directly contact each other. The auxiliary electrode 221 a and thefirst electrode 221 may be made of the same material and may be formedas the same layer.

For example, when the first electrode 221 acts as an anode electrode,the auxiliary electrode 221 a may be formed via the same patterningprocess as a patterning process for forming the anode electrode. Thus,the auxiliary electrode 221 a may be spaced apart from the anodeelectrode.

The auxiliary electrode 221 a serves as a bridge electrode thatelectrically connects the second electrode 225 to the VSS voltageconnection line 323 in the display region. Therefore, the auxiliaryelectrode 221 a is formed on the VSS voltage connection line 323, andcontacts the VSS voltage connection line 323 and electrically connectsthereto.

In other words, in an embodiment of the present disclosure, the VSSvoltage connection line 323 is disposed in the display region. Thus, theauxiliary electrode 221 a and the VSS voltage connection line 323 maycontact each other within the display region. Therefore, a contact-holemay be formed in a passivation layer 218 covering the VSS voltageconnection line 323. Via the contact-hole, the auxiliary electrode 221 aand the VSS voltage connection line 323 may be electrically connected toeach other.

On the auxiliary electrode 221 a, a bank layer 231 may be disposed. Thebank layer 231 may extend along a boundary between the line region CLAand the transmissive region TA. The bank layer 231 may be patterned tocover each of both ends of the auxiliary electrode 221 a. Thus, aportion of the auxiliary electrode 221 a which is not covered with thebank layer 231 may be exposed to an outside.

A boundary portion as the bank layer 231 extending to cover each of theboth ends of the auxiliary electrode 221 a may act as a boundary betweenthe non-transmissive region NTA and the transmissive region TA.Therefore, the auxiliary electrode 221 a may be formed to correspond tothe line region CLA, and thus may be disposed in the non-transmissiveregion NTA. For example, the auxiliary electrode 221 a may be formed tocorrespond to a distal end of each of a pair of data lines 313. However,the present disclosure is not limited thereto.

On a portion of the auxiliary electrode 221 a between opposing adjacentbank layers 231 covering the both ends of the auxiliary electrode 221 arespectively, the partition wall 241 may be formed. The partition wall241 has a width W₄ of a top face larger than a width W₅ of a bottomface. Thus, the partition wall 24 may have an inverse tapered shape.However, the present disclosure is not limited thereto. The partitionwall 241 may be disposed on the auxiliary electrode 221 a and maycontact the auxiliary electrode 221 a.

Since the width W₄ of the top face of the partition wall 241 is largerthan the width W₅ of the bottom face thereof, the top face of thepartition wall 241 acts as a kind of an eave. Therefore, the auxiliaryelectrode 221 a disposed under the partition wall 241 may have a regionin which the auxiliary electrode 221 a overlaps the top face of thepartition wall 241 serving as the eave, but is not in contact with thepartition wall 241. The auxiliary electrode 221 a and the secondelectrode 225 contact directly each other in this region to form theelectrode contact EC.

That is, the electrode contact EC composed of a portion of the auxiliaryelectrode 221 a and a portion of the second electrode 225 which contactdirectly each other is disposed inside of a region of the partition wall241. In other words, the electrode contact EC is disposed in innerregion than end of the partition wall 241, so the electrode contact ECis disposed inwardly than end of the partition wall 241. Accordingly,the electrode contact EC overlaps the top face of the partition wall 241and is positioned under the partition wall 241.

Specifically, the partition wall 241 includes a first partition wallstructure 241 a and a second partition wall structure 241 b stacked onthe first partition wall structure 241 a.

Therefore, the electrode contact EC is disposed in a region between onedistal end of the first partition wall structure 241 a and one distalend of the second partition wall structure 241 b. Specifically, theelectrode contact EC is located in a portion of this region in which theauxiliary electrode 221 a is exposed to an outside.

The first partition wall structure 241 a may be in contact with theauxiliary electrode 221 a, while the second partition wall structure 241b may be spaced apart from the auxiliary electrode 221 a. Further, thefirst partition wall structure 241 a may overlap the second partitionwall structure 241 b, and may be disposed inside of a region of thesecond partition wall structure 241 b. In other words, the firstpartition wall structure 241 a is disposed in inner region than end ofthe second partition wall structure 241 b, so the first partition wallstructure 241 a is disposed inwardly than end of the second partitionwall structure 241 b.

A bottom face of the first partition wall structure 241 a acts as thebottom face of the partition wall 241, while a top face of the secondpartition wall structure 241 b acts as the top face of the partitionwall 241. The first partition wall structure 241 a and the bank layer231 may be made of the same material, and may constitute the same layer.The first partition wall structure 241 a may be formed to be spacedapart from the bank layer 231 covering each of the both ends of theauxiliary electrode 221 a.

Therefore, the bank layer 231 may be absent in a region between thefirst partition wall structure 241 a and each of the bank layers 231covering the both ends of the auxiliary electrode 221 a, respectively.Thus, this region may act as an open region BO of the bank layer wherethe auxiliary electrode 221 a is exposed to an outside.

In this case, the distal end of the second partition wall structure 241b, that is, the eave of the second partition wall structure 241 b maynot overlap the bank layer 231 disposed on each of both ends of thepartition wall 241 so as to increase an area of the open region BO ofthe bank layer as much as possible.

In this case, it is preferable that the eave of the second partitionwall structure 241 b coincides with the boundary of the bank layer 231or is spaced apart therefrom by a certain distance. That is, it isdesirable that a width of the open region BO of the bank layer is atleast equal to or larger than a width of the electrode contact EC.

In particular, when the eave of the second partition wall structure 241b coincides with the boundary of the bank layer 231, the electricalresistance of the second electrode may be reduced while an area of thetransmission region may be secured as much as possible.

Thus, when the eave of the second partition wall structure 241 b doesnot overlap the bank layer 231 or is spaced apart therefrom by a certaindistance, a region of the electrode contact EC composed of a portion ofthe auxiliary electrode 221 a and a portion of the second electrode 225which contact directly each other may be secured as much as possible.

The first partition wall structure 241 a may be patterned using the samemask process as a mask process for forming the bank layer 231. The firstpartition wall structure 241 a may have the same shape as the bank layer231. However, the present disclosure is not limited thereto.

The first partition wall structure 241 a may have a non-inverse taperedshape in which the first partition wall structure 241 a is graduallynarrowed as the first partition wall structure 241 a extends upwardly. Alateral face (or a lateral surface) 241 c of the first partition wallstructure 241 a may be gently curved.

The second partition wall structure 241 b may be made of a photoresistmaterial. For example, the second partition wall structure 241 b may bemade of a negative photoresist material. However, the present disclosureis not limited thereto.

The second partition wall structure 241 b may have an inverse taperedshape in which the second partition wall structure 241 b is graduallynarrowed as the second partition wall structure 241 b extendsdownwardly. A lateral face (or a lateral surface) 241 d of the secondpartition wall structure 241 b may be gently curved.

For example, when the second partition wall structure 241 b is made of anegative photoresist material, the second partition wall structure 241 bmay be formed as follows.

First, a negative photoresist material is applied to cover the firstpartition wall structure 241 a, and then a partial region of thematerial is exposed to a material such as a polymerization initiatorthrough a mask. The region of the negative photoresist exposed to thepolymerization initiator is cured via a thermal curing step to form aninverse tapered shape. Then, a rest of the negative photoresistexcluding the inverse tapered shape structure is removed via a liquidchemical infiltration process, thereby to form the second partition wallstructure 241 b of an inverse tapered shape.

That is, although the partition wall 241 according to an embodiment ofthe present disclosure includes the first partition wall structure 241 ahaving a non-inverse tapered shape and the second partition wallstructure 241 b having an inverse tapered shape stacked on the firstpartition wall structure 241 a, an overall shape of the partition wall241 may have an inverse tapered shape in which a width W₄ of the topface thereof is larger than a width W₅ of the bottom face thereofbecause the width W₄ of the top face of the second partition wallstructure 241 b is larger than the width W₅ of the bottom face of thefirst partition wall structure 241 a, as shown in FIG. 46A.

Due to the above shape of the partition wall 241, the auxiliaryelectrode region AE includes the electrode contact EC composed of aportion of the auxiliary electrode 221 a and a portion of the secondelectrode 225 which directly contact each other.

Specifically, at least a portion of a removed region of the bank layer231 located in a region of the partition wall 241 may be a region of theelectrode contact EC. Since the partition wall 241 has the width W₄ ofthe top face thereof larger than the width W₅ of the bottom facethereof, an at least a portion of a removed region of the bank layer 231may be screened with a top face of the partition wall 241 and may notcontact a bottom face of the partition wall 241, such that the auxiliaryelectrode 221 a may be exposed to the outside.

In this way, the portion of the auxiliary electrode 221 a which isscreened with the top face of the partition wall 241 but does notcontact the bottom face of the partition wall 241 may constitute theelectrode contact EC.

For example, when the organic light-emitting layer 223 and the secondelectrode 225 are formed over an entirety of the display region, theauxiliary electrode 221 a and the second electrode 225 may not be indirect contact with each other because the organic light-emitting layer223 and the second electrode 225 are sequentially stacked on theauxiliary electrode 221 a as exposed to an outside in absence of thepartition wall 241.

Further, even in presence of the partition wall 241, the organiclight-emitting layer 223 and the second electrode 225 are formed alongthe partition wall 241 and are connected to each other when thepartition wall 241 has a non-inverse tapered shape in which the width W₄of the top face of the partition wall 241 is smaller than the width W₅of the bottom face thereof. Thus, the organic light-emitting layer 223and the second electrode 225 are sequentially stacked on the auxiliaryelectrode 221 a, so that the auxiliary electrode 221 a and the secondelectrode 225 may not directly contact each other.

However, as in one embodiment of the present disclosure, when the widthW₄ of the top face of the partition wall 241 is larger than the width W₅of the bottom face thereof, the organic light-emitting layer 223 may bediscontinuous (this discontinuity may occur due to the partition wall241) although the organic light-emitting layer 223 is disposed on theentirety of the display region. Further, the second electrode 225 may bedisposed on the entirety of the display region, but may not bediscontinuous.

This configuration is due to the low diffraction property of the organiclight-emitting layer 223 and the high diffraction property of the secondelectrode 225. Specifically, the organic light-emitting layer 223 isformed by depositing a material having low diffraction property and highlinearity. Thus, the material forming the organic light-emitting layer223 does not penetrate well to an inner region of the auxiliaryelectrode 221 a which is screened with the top face of the partitionwall 241 which serves as the eave, such that the organic light-emittinglayer 223 may not be formed.

Thus, the organic light-emitting layer 223 may be formed in an islandform and on the top face of partition wall 241. However, the organiclight-emitting layer 223 may not be formed on the auxiliary electrode221 a that is screened with the partition wall 241. Thus, the organiclight-emitting layer 223 may be discontinuous (this discontinuity mayoccur due to the partition wall 241).

To the contrary, the second electrode 225 is formed by depositing amaterial having high diffraction properties such as IZO. Thus, thematerial forming the second electrode 225 may penetrate well to an innerregion of the auxiliary electrode 221 a which is screened with the topface of the partition wall 241 which acts like the eave, such that thesecond electrode 225 may be formed.

In particular, the second electrode 225 may be made of a material havinghigh diffraction property, and, thus may penetrate to a region of thepartition wall 241 and cover a side face of the partition wall 241.Thus, the second electrode 225 may be deposited to surround thepartition wall 241, and thus the second electrode 225 may not bediscontinuous.

In one example, as shown in FIG. 46B, in a region where the firstpartition wall structure 241 a and the second partition wall structure241 b contact each other, a bottom face 241 e of the second partitionwall structure 241 b may extend in an upwardly inclined manner towardthe top face of the second partition wall structure 241 b. Thus, a pathof the second electrode 225 surrounding the partition wall 241 may belonger and the second electrode 225 may be continuous.

Further, each of lateral faces of the first partition wall structure 241a and the second partition wall structure 241 b may be gently curved,thereby to prevent the second electrode 225 surrounding the partitionwall 241 from being discontinuous.

As shown in FIG. 46B, in some embodiments, an inward region IW of thepartition wall 241 may be defined as a region between one side end 241 fof the first partition wall structure 241 a and one side end 241 g ofthe second partition wall structure 241 b.

As described above, according to an embodiment of the presentdisclosure, the second electrode surrounding the partition wall may havethe longer path and may be continuous. Thus, a contact area thereof withthe auxiliary electrode may be larger compared to a case where thesecond electrode is discontinuous. Thus, effect of reducing luminancenon-uniformity may be more effectively achieved by reducing theelectrical resistance of the second electrode.

As shown in FIG. 45 , one example in which the second electrode 225 isdeposited to surround the partition wall 241 and the second electrode225 is not discontinuous is set forth. However, the present disclosureis not limited thereto. The second electrode 225 may be discontinuousdue to the partition wall 241.

Although the second electrode 225 is discontinuous due to the partitionwall 241, the electrode contact EC composed of the portion of theauxiliary electrode 221 a and the portion of the second electrode 225directly contacting each other may be formed because the secondelectrode 225 has better diffraction than that of the organiclight-emitting layer 223, and thus penetrates deeply to the region ofthe partition wall 241.

Therefore, the organic light-emitting layer 223 may be absent on an atleast a portion of a region where the auxiliary electrode 221 a overlapsthe partition wall 241 but does not contact the partition wall 241,specifically, a portion of the auxiliary electrode 221 a close to abottom of the partition wall 241. The electrode contact EC composed ofthe portion of the auxiliary electrode 221 a and a portion of the secondelectrode 225 which are in direct contact with each other may be formed.

In this way, the second electrode 225 makes contact with the auxiliaryelectrode 221 a via the electrode contact EC, and the auxiliaryelectrode 221 a is electrically connected to and contacts the VSSvoltage connection line 323. As a result, the second electrode 225 maybe electrically connected to the VSS voltage connection line 323.

As described above, when the second electrode 225 as a transparentelectrode having a high sheet resistance is used, differences betweenthe low-level voltage VSS rise values at various positions in thedisplay panel position increase. As a result, the non-uniformityphenomenon of luminance in the display panel occurs, which may lead to aproblem of deterioration of display quality.

However, as in one embodiment of the present disclosure, the auxiliaryelectrode region AE including the partition wall 241 whose the width W₄of the top face is larger than the width W₅ of the bottom face thereofis disposed on the line region CLA in the display region. The secondelectrode 225 of the organic light-emitting element 220 and the VSSvoltage connection line 323 may be electrically connected to each othervia the auxiliary electrode 221 a, thereby to reduce the electricalresistance of the second electrode 225 as a transparent electrode.

Further, as in one embodiment of the present disclosure, the partitionwall 241 whose the width W₄ of the top face is larger than the width W₅of the bottom face thereof is included in the auxiliary electrode regionAE. Thus the organic light-emitting layer 223 may be discontinuous andthe second electrode 225 may be prevented from being discontinuous evenin the presence of the partition wall 241. Thus, a separate mask processis not required, thereby increasing the efficiency of the process.

In one example, it is preferable that the organic light-emitting layer223 is not formed on a portion of the auxiliary electrode 221 a asscreened with the top face of the partition wall 241. However, theorganic light-emitting layer 223 may penetrate to a portion of theregion of the partition wall 241 and thus be formed on the auxiliaryelectrode 221 a.

This may be caused by a design error of the partition wall 241 or otherprocess errors. Further, this may occur because the material forming theorganic light-emitting layer 223 has the low diffractive property.

Therefore, when the organic light-emitting layer 223 penetrates to aportion of the region of the partition wall 241 and is formed on theauxiliary electrode 221 a, the area of the electrode contact ECdecreases as much as an area where the organic light-emitting layer 223is formed. Thus, the contact area between the auxiliary electrode 221 aand the second electrode 225 may be reduced.

When the area of the electrode contact EC decreases, the electricalresistance of the second electrode 225 increases correspondingly. Thus,it may be difficult to reduce or minimize luminance non-uniformity ofthe entire panel region.

Thus, when the partition wall 241 in which the second partition wallstructure 241 b is stacked on the first partition wall structure 241 aas a portion of the bank layer 231 and is separated from the auxiliaryelectrode 221 a is introduced, the area of the electrode contact EC maybe further increased, further reducing the electrical resistance of thesecond electrode 225 as a transparent electrode.

For example, FIG. 47A shows a region of an electrode contact EC that maybe formed when a partition wall 241 of a single layer having an inversetapered shape is formed. FIG. 47B shows a region of an electrode contactEC that may be formed when a partition wall 241 including a stack of afirst partition wall structure and a second partition wall structure ofan inverse tapered shape as one embodiment of the present disclosure.

As shown in FIG. 47A, when the partition wall 241 has an inverse taperedshape but is formed of a single layer, the area where the partition wall241 contacts the auxiliary electrode 221 a increases. Thus, the area ofthe auxiliary electrode 221 a which is screened with the top face of thepartition wall 241 but is exposed to the outside may not be relativelylarge. Accordingly, the area of the electrode contact EC composed of aportion of the auxiliary electrode 221 a and a portion of the secondelectrode 225 directly contacting each other and disposed inside of theregion of the partition wall 241 may not be relatively large.

However, as shown in FIG. 47B, when the partition wall 241 is formed bystacking the second partition wall structure 241 b of the inversetapered shape on the first partition wall structure 241 a, only thefirst partition wall structure 241 a contacts the auxiliary electrode221 a, and the second partition wall structure 241 b is spaced apartfrom the auxiliary electrode 221 a. Therefore, the area of the auxiliaryelectrode 221 a which is screened with the top face of the partitionwall 241 but is exposed to the outside may be relatively large. As aresult, the area of the electrode contact EC composed of a portion ofthe auxiliary electrode 221 a and a portion of the second electrode 225directly contacting each other and disposed inside of the region of thepartition wall 241 may be relatively large.

That is, assuming that a size of the partition wall 241 shown in FIG.47A and a size of the second partition wall structure 241 b shown inFIG. 47B are the same, the area of the electrode contact EC may increasewhen the partition wall 241 is formed by stacking the second partitionwall structure 241 b of the inverse tapered shape on the first partitionwall structure 241 a as shown in FIG. 47B.

Therefore, when introducing the partition wall 241 structure in whichthe second partition wall structure 241 b is stacked on the firstpartition wall structure 241 a as a portion of the bank layer 231 and isspaced apart from the auxiliary electrode 221 a as in an embodiment ofthe present disclosure, the area of the electrode contact EC may befurther increased, further reducing the electrical resistance of thesecond electrode 225. Further, the size of the partition wall 241 may bereduced to improve transmittance.

Further, according to an embodiment of the present disclosure, theauxiliary electrode region AE is formed on each of a plurality of lineregions CLA respectively including VSS voltage connection lines 323extending across the display region. Thus, the electrical connectionbetween the VSS voltage connection line 323 and the auxiliary electrode221 a may occur within the display region. Thus, the current may besupplied to each pixel in the display region in a smooth manner. Thus,the luminance distribution across the panel may be made more uniform.

For example, when the VSS voltage connection line 323 is not disposed inthe display region, but surrounds the display region as the bezel of thenon-display region does, the electrical connection of the VSS voltageconnection line 323 and the auxiliary electrode 221 a may occur in thenon-display region.

Especially, in a large area transparent display device, a differencebetween the VSS voltage supplied to a pixel near the VSS voltageconnection line 323 and the VSS voltage supplied to the pixel in acentral portion of the display region far away from the VSS voltageconnection line 323 may be large. Thus, the difference between thelow-level voltage VSS rise values at the positions of the display panelmay increase.

However, as in one embodiment of the present disclosure, each of theplurality of line regions CLA respectively including the VSS voltageconnection lines 323 may extend across the display region. In this case,variations of the distances between the multiple of pixels existing inthe display panel and the VSS voltage connection lines 323 may be small.Thus, the difference between the low-level voltage VSS rise values atthe positions of the display panel may decrease.

Further, the partition wall 241 of the auxiliary electrode region AE maybe used as a spacer. Thus, a process to form a separate spacer and aseparate region to form a spacer are not required, so that high processefficiency and panel space utilization may be obtained.

FIG. 48A and FIG. 48B show ΔVSS values in a case where the partitionwall 241 is present and a case in where the partition wall 241 isabsent, respectively. Specifically, FIG. 48A and FIG. 48B showmeasurements of the low-level voltages VSS of the pixels based on thepanel with the number of horizontal pixels of the panel X the number ofvertical pixels of the panel being 1440×540.

As shown in FIG. 48A, ΔVSS=1.0161V as the difference between the minimumand maximum values of the low-level voltage was measured when there isno partition wall. On the other hand, as shown in FIG. 48B, ΔVSS=0.2084Vas the difference between the minimum and maximum values of thelow-level voltage was measured when there is the partition wall.

Accordingly, it may be seen that the difference between the rise valuesof the low-level voltage VS S at the positions of the panel isremarkably smaller when there is the partition wall, compared to thecase where there is no partition wall, thereby reducing or minimizingthe non-uniformity of luminance.

FIG. 49A shows variations of an area and an electrical resistance of anelectrode contact based on a width of the partition wall.

As shown in FIG. 49A, the electrode contact area increases as the widthof the top face of the partition wall increases. Thus, the electricalresistance of the second electrode is reduced. In other words, theelectrode contact area and the electrical resistance of the secondelectrode are inversely proportional to each other. Thus, increasing thewidth of the top face of the partition wall may allow increasing ormaximizing the electrode contact area, such that the electricalresistance of the second electrode is reduced.

FIG. 49B shows variations of an area and an electrical resistance of anelectrode contact based on a size of the open region BO of the banklayer.

As may be seen in FIG. 49B, the area of the electrode contact increasesas the width of the open region of the bank layer increases. Thus, theelectrical resistance of the second electrode is reduced.

In particular, in a section where the width of the open region of thebank layer is smaller than or equal to a certain width, specifically, ina section where the width of the open region of the bank layer is 1.75μm or smaller, the area of the electrode contact increases rapidly.Thus, the electrical resistance of the second electrode is reduced. Inthis section, the eave of the partition wall begins to at leastpartially overlap the bank layer. The eave of the partition wall atleast partially overlaps the bank layer, such that the width of the openregion of the bank layer becomes smaller than the width of the electrodecontact. Thus, the area of the electrode contact may be reducedcorrespondingly.

However, in a section where the width of the open region of the banklayer is 1.75 μm or greater, that is, in a section where the eave of thepartition wall does not overlap the bank layer, the area of theelectrode contact increases as the width of the open region of the banklayer increases. Thus, the electrical resistance of the second electrodeis reduced correspondingly.

In one example, in a section where the width of the open region of thebank layer is 3.75 μm or greater, the area of the electrode contact isno longer increased and becomes constant. Thus, in order to secure thetransmission region as much as possible, it is desirable to set thewidth of the open region of the bank layer to 3.75 μm or smaller.

The present disclosure may include following aspects andimplementations.

A first aspect of the present disclosure provides a transparent displaypanel including a display region and a non-display region, wherein thedisplay region includes: a plurality of light-emitting regions; aplurality of transmissive regions; a plurality of line regions spacedfrom each other, each line region extending in one direction; and aplurality of auxiliary electrode regions arranged on a correspondingline region; wherein the light-emitting region includes an organiclight-emitting element including a first electrode, an organiclight-emitting layer, and a second electrode, wherein at least one ofthe line regions includes a VSS voltage connection line, wherein theauxiliary electrode region is disposed on the line region including theVSS voltage connection line, wherein the auxiliary electrode regionincludes: an auxiliary electrode electrically connected to the VSSvoltage connection line; a partition wall disposed on the auxiliaryelectrode, wherein a width of a top face of the partition wall is largerthan a width of a bottom face thereof; and an electrode contact composedof a portion of the auxiliary electrode and a portion of the secondelectrode which directly contact each other, wherein the electrodecontact is positioned inwardly than end of the partition wall.

In one implementation of the first aspect, the light-emitting regionincludes a first color light-emitting region, a second colorlight-emitting region and a third color light-emitting region, whereineach of the second color light-emitting region and the third colorlight-emitting region is disposed on a corresponding line region,wherein the first color light-emitting region is disposed between thesecond color light-emitting region and the third color light-emittingregion disposed on the different line regions, respectively, wherein theauxiliary electrode region is disposed between the second colorlight-emitting region and the third color light-emitting region disposedon the same line region.

In one implementation of the first aspect, the second electrode is madeof indium zinc oxide (IZO).

In one implementation of the first aspect, the partition wall includes afirst partition wall structure and a second partition wall structurestacked on the first partition wall structure, wherein the firstpartition wall structure is in contact with the auxiliary electrode,wherein the second partition wall structure is spaced apart from theauxiliary electrode.

In one implementation of the first aspect, a lateral face of the secondpartition wall structure is curved.

In one implementation of the first aspect, in a region where the firstpartition wall structure contacts the second partition wall structure, abottom face of the second partition wall structure extends in an upwardinclined manner toward the top face of the second partition wallstructure.

In one implementation of the first aspect, the first partition wallstructure overlaps the second partition wall structure, and is disposedinwardly than end of the second partition wall structure.

In one implementation of the first aspect, the transparent display panelfurther comprises a bank layer extending along a boundary between theline region and the transmissive region, wherein the first partitionwall structure and the bank layer are made of the same material andconstitute the same layer.

In one implementation of the first aspect, the second partition wallstructure and the bank layer do not overlap each other.

In one implementation of the first aspect, the auxiliary electrode andthe first electrode are made of the same material and constitute thesame layer.

In one implementation of the first aspect, the transparent display panelfurther comprises a first VSS voltage line and a second VSS voltage linedisposed in the non-display region while the display region isinterposed therebetween, wherein the VSS voltage connection lineelectrically connects the first VSS voltage line and the second VSSvoltage line to each other.

In one implementation of the first aspect, the electrode contact is aregion between one side end of the first partition wall structure andone side end of the second partition wall structure.

A second aspect of the present disclosure provides a transparent displaydevice including the transparent display panel as defined above, a datadriver supplying a data voltage to the transparent display panel, a gatedriver supplying a scan signal to the transparent display panel, and atiming controller that controls the gate driver and the data driver.

As described above, the present disclosure is described with referenceto the drawings. However, the present disclosure is not limited by theembodiments and drawings disclosed in the present specification. It willbe apparent that various modifications may be made thereto by thoseskilled in the art within the scope of the present disclosure.Furthermore, although the effect resulting from the features of thepresent disclosure has not been explicitly described in the descriptionof the embodiments of the present disclosure, it is obvious that apredictable effect resulting from the features of the present disclosureshould be recognized.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

The invention claimed is:
 1. A transparent display panel including adisplay region and a non-display region, the display region comprising:a plurality of light-emitting regions; a plurality of transmissiveregions; and a plurality of line regions spaced apart from each other,each line region extending in one direction, wherein the light-emittingregion includes an organic light-emitting element including a firstelectrode, an organic light-emitting layer, and a second electrode,wherein at least one of the line regions includes a VSS voltageconnection line, wherein an auxiliary electrode region is on the lineregion including the VSS voltage connection line, wherein the auxiliaryelectrode region includes: an auxiliary electrode electrically connectedto the VSS voltage connection line; a partition wall disposed on theauxiliary electrode, wherein a width of a top face of the partition wallis larger than a width of a bottom face thereof, wherein the top face ofthe partition wall is opposite the bottom face of the partition wall;and an electrode contact including a portion of the auxiliary electrodeand a portion of the second electrode which contact each other and areelectrically connected to each other, wherein the electrode contact ispositioned inwardly with respect to an end of the partition wall,wherein the partition wall includes a first partition wall structure anda second partition wall structure stacked on the first partition wallstructure, wherein the first partition wall structure is in contact withthe auxiliary electrode, wherein the second partition wall structure isspaced apart from the auxiliary electrode, and wherein a lateral face ofthe second partition wall structure is curved.
 2. The transparentdisplay panel of claim 1, wherein the light-emitting region includes afirst color light-emitting region, a second color light-emitting region,and a third color light-emitting region, wherein each of the secondcolor light-emitting region and the third color light-emitting region ison a corresponding line region, wherein the first color light-emittingregion is disposed between the second color light-emitting region andthe third color light-emitting region on different line regions, andwherein the auxiliary electrode region is disposed between the secondcolor light-emitting region and the third color light-emitting region ona same line region.
 3. The transparent display panel of claim 1, whereinthe second electrode is made of indium zinc oxide.
 4. The transparentdisplay panel of claim 1, wherein a width of a top face of the secondpartition wall structure is larger than a width of a bottom face of thefirst partition wall structure.
 5. The transparent display panel ofclaim 1, wherein the first partition wall structure has a non-inversetapered shape in which the first partition wall structure is graduallynarrowed as the first partition wall structure extends upwardly.
 6. Thetransparent display panel of claim 1, wherein the second partition wallstructure has an inverse tapered shape in which the second partitionwall structure is gradually narrowed as the second partition wallstructure extends downwardly.
 7. The transparent display panel of claim6, wherein the second partition wall structure and a bank layer do notoverlap with each other.
 8. The transparent display panel of claim 1,wherein in a region where the first partition wall structure contactsthe second partition wall structure, a bottom face of the secondpartition wall structure extends in an upward inclined manner toward thetop face of the second partition wall structure.
 9. The transparentdisplay panel of claim 1, wherein the first partition wall structureoverlaps with the second partition wall structure, and is disposedinwardly with respect to an end of the second partition wall structure.10. The transparent display panel of claim 1, wherein the transparentdisplay panel further comprises a bank layer extending along a boundarybetween the line region and the transmissive region, and wherein thefirst partition wall structure and the bank layer are made of a samematerial and formed as a same layer.
 11. The transparent display panelof claim 10, wherein the bank layer has an open region where theauxiliary electrode is exposed to outside.
 12. The transparent displaypanel of claim 11, wherein the open region has a width in a range from1.75 μm to 3.75 μm.
 13. The transparent display panel of claim 1,wherein the auxiliary electrode and the first electrode are made of asame material and formed as a same layer.
 14. The transparent displaypanel of claim 1, wherein inward region of the partition wall is aregion between one side end of the first partition wall structure andone side end of the second partition wall structure.
 15. The transparentdisplay panel of claim 1, wherein an outer contour of each of theplurality of transmissive regions is at least partially curved.
 16. Thedisplay device of claim 1, wherein the second electrode overlaps thepartition wall.
 17. The display device of claim 1, wherein the secondelectrode fully overlaps the top face of the partition wall.
 18. Atransparent display comprising: a display region and a non-displayregion, the display region comprising: a plurality of light-emittingregions; a plurality of transmissive regions; and a plurality of lineregions spaced apart from each other, each line region extending in onedirection, wherein the light-emitting region includes an organiclight-emitting element including a first electrode, an organiclight-emitting layer, and a second electrode, wherein at least one ofthe line regions includes a VSS voltage connection line, wherein anauxiliary electrode region is on the line region including the VSSvoltage connection line, and wherein the auxiliary electrode regionincludes: an auxiliary electrode electrically connected to the VSSvoltage connection line; a partition wall disposed on the auxiliaryelectrode, wherein a width of a top face of the partition wall is largerthan a width of a bottom face thereof, wherein the top face of thepartition wall is opposite the bottom face of the partition wall; and anelectrode contact including a portion of the auxiliary electrode and aportion of the second electrode which contact each other and areelectrically connected to each other, wherein the electrode contact ispositioned inwardly with respect to an end of the partition wall; andwherein the organic light-emitting layer is formed of a material havinga higher diffraction property than that of the second electrode.
 19. Atransparent display panel comprising: a display region and a non-displayregion, the display region comprising: a plurality of light-emittingregions; a plurality of transmissive regions; and a plurality of lineregions spaced apart from each other, each line region extending in onedirection, wherein the light-emitting region includes an organiclight-emitting element including a first electrode, an organiclight-emitting layer, and a second electrode, wherein at least one ofthe line regions includes a VSS voltage connection line, wherein anauxiliary electrode region is on the line region including the VSSvoltage connection line, and wherein the auxiliary electrode regionincludes: an auxiliary electrode electrically connected to the VSSvoltage connection line; a partition wall disposed on the auxiliaryelectrode, wherein a width of a top face of the partition wall is largerthan a width of a bottom face thereof, wherein the top face of thepartition wall is opposite the bottom face of the partition wall; and anelectrode contact including a portion of the auxiliary electrode and aportion of the second electrode which contact each other and areelectrically connected to each other, wherein the electrode contact ispositioned inwardly with respect to an end of the partition wall; andwherein the transparent display panel further comprises a first VSSvoltage line and a second VSS voltage line disposed in the non-displayregion with the display region interposed therebetween, and wherein theVSS voltage connection line electrically connects the first VSS voltageline and the second VSS voltage line to each other.